### Install pdf-merger-js

Source: https://github.com/nbesli/pdf-merger-js/blob/master/README.md

Commands to install the library locally or globally for CLI usage.

```bash
npm install --save pdf-merger-js
```

```bash
npm install -g pdf-merger-js
```

--------------------------------

### Install PDF Merger CLI

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Commands for installing the package globally or running it locally via npx.

```bash
npm install -g pdf-merger-js
```

```bash
npm install pdf-merger-js
npx pdf-merge [options] <inputFiles...>
```

--------------------------------

### Check Version

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Displays the installed version of the CLI.

```bash
pdf-merge -V
# Output: 5.1.2
```

--------------------------------

### CLI Output Messages

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Examples of standard, verbose, and silent output modes.

```text
Merged pages successfully into <filename>
```

```text
adding page(s) <pages> from <input> to output...
[repeated for each input]
Saving merged output to <filename>...
Merged pages successfully into <filename>
```

```text
[No output to stdout]
```

--------------------------------

### Simple Merge Example

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Basic command to merge two local PDF files.

```bash
pdf-merge -o output.pdf input1.pdf input2.pdf
```

--------------------------------

### CLI Usage Examples

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Common command-line interface operations for merging PDF files, selecting pages, and managing output settings.

```bash
# Basic merge
pdf-merge -o output.pdf input1.pdf input2.pdf

# With page selection
pdf-merge -o output.pdf 'input1.pdf#1-3' 'input2.pdf#5'

# Verbose output
pdf-merge -v -o output.pdf input1.pdf input2.pdf

# Silent mode
pdf-merge -s -o output.pdf input1.pdf input2.pdf

# From URLs
pdf-merge -o output.pdf 'https://example.com/file.pdf#1-3'

# Show version
pdf-merge -V

# Show help
pdf-merge -h
```

--------------------------------

### Merge PDFs in Node.js

Source: https://github.com/nbesli/pdf-merger-js/blob/master/README.md

Asynchronous example demonstrating how to add pages, set metadata, and save the resulting PDF.

```js
import PDFMerger from 'pdf-merger-js';

var merger = new PDFMerger();

(async () => {
  await merger.add('pdf1.pdf');  //merge all pages. parameter is the path to file and filename.
  await merger.add('pdf2.pdf', 2); // merge only page 2
  await merger.add('pdf2.pdf', [1, 3]); // merge the pages 1 and 3
  await merger.add('pdf2.pdf', '4, 7, 8'); // merge the pages 4, 7 and 8
  await merger.add('pdf3.pdf', '3 to 5'); //merge pages 3 to 5 (3,4,5)
  await merger.add('pdf3.pdf', '3-5'); //merge pages 3 to 5 (3,4,5)

  // Set metadata
  await merger.setMetadata({
    producer: "pdf-merger-js based script",
    author: "John Doe",
    creator: "John Doe",
    title: "My live as John Doe"
  });

  await merger.save('merged.pdf'); //save under given name and reset the internal document
  
  // Export the merged PDF as a nodejs Buffer
  // const mergedPdfBuffer = await merger.saveAsBuffer();
  // fs.writeSync('merged.pdf', mergedPdfBuffer);
})();
```

--------------------------------

### Specify Output File

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Examples of defining the destination path for the merged PDF.

```bash
pdf-merge -o ./merged.pdf input1.pdf input2.pdf
pdf-merge --output /tmp/result.pdf input1.pdf input2.pdf
```

--------------------------------

### CLI usage for PDF merging

Source: https://github.com/nbesli/pdf-merger-js/blob/master/README.md

Command line interface help and example calls for merging local and remote PDF files.

```txt
Usage: pdf-merge [options] <inputFiles...>

merge multiple PDF documents, or parts of them, to a new PDF document

Options:
  -V, --version              output the version number
  -o, --output <outputFile>  Merged PDF output file path
  -v, --verbose              Print verbose output
  -s, --silent               do not print any output to stdout. Overwrites --verbose
  -h, --help                 display help for command
```

```bash
pdf-merge --output ./merged.pdf ./input1.pdf#1-2 ./input2.pdf#1,2,5-7
```

```bash
pdf-merge --verbose --output ./sample.pdf Testfile.pdf https://pdfobject.com/pdf/sample.pdf https://upload.wikimedia.org/wikipedia/commons/1/13/Example.pdf#2-3
```

--------------------------------

### Merge PDFs in React

Source: https://github.com/nbesli/pdf-merger-js/blob/master/README.md

Example of using the browser-specific build to merge File or Blob objects and display the result in an iframe.

```jsx
import PDFMerger from 'pdf-merger-js/browser';
import React, { useEffect, useState } from 'react';

// files: Array of PDF File or Blob objects
const Merger = (files) => {
  const [mergedPdfUrl, setMergedPdfUrl] = useState();

  useEffect(() => {
    const render = async () => {
      const merger = new PDFMerger();

      for(const file of files) {
        await merger.add(file);
      }

      await merger.setMetadata({
        producer: "pdf-merger-js based script"
      });

      const mergedPdf = await merger.saveAsBlob();
      const url = URL.createObjectURL(mergedPdf);

      return setMergedPdfUrl(url);
    };

    render().catch((err) => {
      throw err;
    });

    () => setMergedPdfUrl({});
  }, [files, setMergedPdfUrl]);

  return !data ? (
    <>Loading</>
  ) : (
    <iframe
      height={1000}
      src={`${mergedPdfUrl}`}
      title='pdf-viewer'
      width='100%s'
    ></iframe>
  );
};
```

--------------------------------

### Error Cases for parsePagesString

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

Examples of invalid inputs that cause the function to throw an Error.

```javascript
parsePagesString()              // Error: not a string
parsePagesString(null)          // Error: not a string
parsePagesString({})            // Error: not a string

parsePagesString('')            // Error: empty string
parsePagesString('-1to-3')      // Error: negative numbers
parsePagesString('1--3')        // Error: double hyphen
parsePagesString('1 until 3')   // Error: invalid keyword ("until" not supported)
parsePagesString('1-')          // Error: incomplete range
parsePagesString('10e3')        // Error: scientific notation not supported
```

--------------------------------

### Triggering Node.js Input Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Examples of inputs that trigger path or URL resolution errors in the Node.js environment.

```javascript
await merger.add('./nonexistent.pdf');      // File not found, invalid URL
await merger.add('not a path or url');      // Invalid format
await merger.add('ht!tp://bad-url.com');    // Malformed URL
```

--------------------------------

### Triggering Input Validation Errors in PDFMerger.add()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Examples of invalid inputs passed to the add method that trigger validation errors.

```javascript
await merger.add(pdf, {});              // Object type not accepted
await merger.add(pdf, 'invalid-pages'); // Invalid format
await merger.add(pdf, NaN);             // Not a valid number
```

--------------------------------

### Triggering Browser Input Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Examples of inputs that trigger URL validation errors in the browser environment.

```javascript
await merger.add('./local-file.pdf');   // File paths not supported in browser
await merger.add('not a url');          // Invalid URL format
await merger.add('ht!tp://bad.com');    // Malformed URL
```

--------------------------------

### Parse Ranges with Hyphen

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

Inclusive range syntax where both start and end are included. Whitespace around hyphens is allowed.

```javascript
parsePagesString('1-3')     // [1, 2, 3]
parsePagesString(' 1-3 ')   // [1, 2, 3]
parsePagesString(' 1 - 3 ') // [1, 2, 3]
parsePagesString('2-6')     // [2, 3, 4, 5, 6]
```

--------------------------------

### Triggering Input Type Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Examples of invalid input types passed to the add method that trigger type validation errors.

```javascript
await merger.add(123);                  // Number not accepted
await merger.add(true);                 // Boolean not accepted
await merger.add({data: 'pdf'});        // Plain object not accepted
```

--------------------------------

### Display Help Information

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Shows available options and usage instructions.

```bash
pdf-merge -h
# Displays usage and all options
```

--------------------------------

### Running Tests

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Commands to execute the test suite for the project.

```bash
npm test              # Run all tests
npm run test:watch   # Watch mode
```

--------------------------------

### Basic CLI Usage

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Standard syntax for executing the merge command.

```bash
pdf-merge [options] <inputFiles...>
```

--------------------------------

### constructor()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Browser.md

Initializes a new PDFMerger instance for browser environments.

```APIDOC
## constructor()

### Description
Creates a new PDFMerger instance configured for browser environments. The constructor initializes an empty internal PDF document and prepares the merger for page additions.

### Returns
- **PDFMerger** - A new instance of the PDFMerger class.
```

--------------------------------

### Add PDF Inputs

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/types.md

Demonstrates adding various input types including file paths, URLs, and binary data.

```javascript
// File path
await merger.add('./document.pdf');

// URL
await merger.add('https://example.com/file.pdf');

// Buffer
const buffer = fs.readFileSync('./file.pdf');
await merger.add(buffer);

// Uint8Array
const uint8 = new Uint8Array([...]);
await merger.add(uint8);
```

--------------------------------

### Initialize PDFMergerBase

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMergerBase.md

Constructor for the base class, initializing an empty internal PDF document.

```javascript
constructor()
```

--------------------------------

### Initialize PDFMerger

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/configuration.md

The constructor requires no parameters to initialize the library.

```javascript
const merger = new PDFMerger();
```

--------------------------------

### CLI Tool Options

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/configuration.md

Available command-line arguments for the pdf-merge utility.

```bash
pdf-merge [options] <inputFiles...>

Options:
  -V, --version              output the version number
  -o, --output <outputFile>  Merged PDF output file path
  -v, --verbose              Print verbose output
  -s, --silent               do not print any output to stdout. Overwrites --verbose
  -h, --help                 display help for command
```

--------------------------------

### Initialize internal PDF document

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMergerBase.md

Ensures an internal PDFDocument instance exists, creating one with default metadata if necessary.

```javascript
async _ensureDoc(): Promise<void>
```

--------------------------------

### Enable Verbose Output

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Displays detailed processing information during the merge.

```bash
pdf-merge -v -o merged.pdf input1.pdf input2.pdf#1-3
# Output:
# adding all pages from input1.pdf to output...
# adding pages 1,2,3 from input2.pdf to output...
# Saving merged output to merged.pdf...
# Merged pages successfully into merged.pdf
```

--------------------------------

### Add PDF Inputs in Browser

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/types.md

Demonstrates adding various input types to the PDF merger instance in a browser environment.

```javascript
// File from input element
const file = document.querySelector('input[type="file"]').files[0];
await merger.add(file);

// Blob from fetch
const blob = await fetch('https://example.com/file.pdf').then(r => r.blob());
await merger.add(blob);

// URL string
await merger.add('https://example.com/file.pdf');

// Uint8Array
const uint8 = new Uint8Array([...]);
await merger.add(uint8);
```

--------------------------------

### Project File Structure

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/INDEX.md

The directory layout of the documentation files within the project.

```text
output/
├── INDEX.md                           # This file
├── README.md                          # Overview and quick reference
├── types.md                           # Type definitions
├── configuration.md                   # Configuration options
├── errors.md                          # Error reference
├── cli.md                             # CLI documentation
└── api-reference/
    ├── PDFMerger-Node.md             # Node.js API
    ├── PDFMerger-Browser.md          # Browser API
    ├── PDFMergerBase.md              # Base class
    └── parsePagesString.md           # Page parser
```

--------------------------------

### Merge Remote Files with Verbose Output

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Download and merge multiple remote files while displaying detailed process information.

```bash
pdf-merge --verbose --output sample.pdf \
  Testfile.pdf \
  https://pdfobject.com/pdf/sample.pdf \
  'https://upload.wikimedia.org/wikipedia/commons/1/13/Example.pdf#2-3'
```

--------------------------------

### Verbose Mode for Debugging

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Run with the -v flag to see detailed information about the merge process.

```bash
pdf-merge -v -o merged.pdf 'input1.pdf#1-3' 'input2.pdf#5'
# Output:
# adding pages 1,2,3 from input1.pdf to output...
# adding page 5 from input2.pdf to output...
# Saving merged output to merged.pdf...
# Merged pages successfully into merged.pdf
```

--------------------------------

### Initialize PDFMerger

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Browser.md

Create a new instance of the PDFMerger class for browser environments.

```javascript
import PDFMerger from 'pdf-merger-js/browser';

const merger = new PDFMerger();
```

--------------------------------

### Default Metadata Initialization

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/configuration.md

Initial metadata values applied when the first page is added to a new PDF document.

```javascript
producer: 'pdf-merger-js'
creationDate: new Date()  // Current date/time
```

--------------------------------

### constructor()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Node.md

Creates a new PDFMerger instance. The constructor initializes an empty internal PDF document and prepares the merger for page additions.

```APIDOC
## constructor()

### Description
Creates a new PDFMerger instance. The constructor initializes an empty internal PDF document and prepares the merger for page additions.

### Returns
- **PDFMerger instance**
```

--------------------------------

### Initialize PDFMerger

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Instantiate a new merger object to begin processing PDF files.

```javascript
new PDFMerger()
```

--------------------------------

### Handle Promise<Buffer> in Node.js

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/types.md

Retrieves a PDF as a Node.js Buffer instance.

```javascript
const buffer = await merger.saveAsBuffer();
// buffer is Node.js Buffer instance
// Can be passed to fs.writeFile(), sent in HTTP response, etc.
```

--------------------------------

### Configure Page Selection

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/configuration.md

Use the add method to specify which pages to include from the input PDF.

```javascript
await merger.add(input);                    // All pages
await merger.add(input, 2);                 // Single page
await merger.add(input, [1, 3, 5]);        // Array of pages
await merger.add(input, '1-3');            // Range format
await merger.add(input, '1,3-5,7');        // Mixed format
```

--------------------------------

### Overriding Default Metadata

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/configuration.md

Demonstrates how to update document metadata after the initial creation using setMetadata.

```javascript
const merger = new PDFMerger();
await merger.add('input.pdf');
// At this point, producer is 'pdf-merger-js'

await merger.setMetadata({ producer: 'CustomApp' });
// Now producer is 'CustomApp'
```

--------------------------------

### Direct Usage of parsePagesString

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

Shows how to import and use the function directly for advanced scenarios.

```javascript
import { parsePagesString } from 'pdf-merger-js';

const pages = parsePagesString('1,5-7,10');
console.log(pages); // [1, 5, 6, 7, 10]
```

--------------------------------

### Handle Missing Input Files Error

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Triggered when no input files are provided to the command.

```bash
$ pdf-merge -o output.pdf
Please provide at least one input file
```

--------------------------------

### add(input, [pages])

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Adds a PDF file to the merge queue, with optional page selection.

```APIDOC
## add(input, [pages])

### Description
Adds pages from a specified PDF input to the current merge session.

### Parameters
- **input** (PdfInput) - Required - The PDF source (file path, URL, Buffer, Blob, etc.).
- **pages** (Page Selection) - Optional - Specific pages to include (e.g., '1-3', [1, 3, 5]).
```

--------------------------------

### Parse Mixed Formats

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

Comma-separated list of individual pages and ranges in any order. Order is preserved from input.

```javascript
parsePagesString('1-3,4')           // [1, 2, 3, 4]
parsePagesString(' 1-3 , 4 , 5')    // [1, 2, 3, 4, 5]
parsePagesString(' 1 - 3, 5-7 ')    // [1, 2, 3, 5, 6, 7]
parsePagesString(' 9,8,1 - 3, 5-6 ,8,9')  // [9, 8, 1, 2, 3, 5, 6, 8, 9]
parsePagesString('2-6,8')           // [2, 3, 4, 5, 6, 8]
parsePagesString('1,3-5,7')         // [1, 3, 4, 5, 7]
parsePagesString('11-13,5,8,16-18,14')    // [11, 12, 13, 5, 8, 16, 17, 18, 14]
```

--------------------------------

### Catching Fetch Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Demonstrates how to catch errors related to missing fetch support when loading PDFs from URLs.

```javascript
try {
  await merger.add('https://example.com/file.pdf');
} catch (error) {
  if (error.message.includes('fetch is not defined')) {
    console.error('Fetch is not available; install a polyfill');
  }
}
```

--------------------------------

### Merge with Page Selection

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Specify pages to include by appending a hash and range to the filename. Quote the argument to prevent shell interpretation of special characters.

```bash
pdf-merge -o merged.pdf 'input.pdf#1-3'
```

```bash
# Single quotes prevent shell interpretation
pdf-merge -o out.pdf 'input.pdf#1-3' 'input2.pdf#5,7'

# Without quotes, some shells may interpret # as comment
pdf-merge -o out.pdf input.pdf#1-3   # May fail depending on shell
```

--------------------------------

### Applying Metadata to PDF Documents

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Metadata application requires at least one page to be added to the merger instance to persist correctly.

```javascript
const merger = new PDFMerger();

// This doesn't error, but metadata won't persist if no pages are added
await merger.setMetadata({ title: 'Test' });

// Metadata only persists if at least one page is added
await merger.add('file.pdf');
```

--------------------------------

### Merge PDFs via Makefile

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Define build targets to automate PDF merging tasks using Make.

```makefile
merge-pdfs:
	pdf-merge -v -o build/merged.pdf \
		docs/intro.pdf \
		'docs/chapter1.pdf#1-20' \
		'docs/chapter2.pdf#1-25' \
		docs/conclusion.pdf

clean:
	rm -f build/merged.pdf
```

--------------------------------

### Add Pages to PDFMerger

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Node.md

Demonstrates various ways to add pages from local files, URLs, or Buffers using different page selection formats.

```javascript
import PDFMerger from 'pdf-merger-js';
const merger = new PDFMerger();

// Add all pages from a local file
await merger.add('./document.pdf');

// Add single page from file
await merger.add('./document.pdf', 2);

// Add multiple pages as array
await merger.add('./document.pdf', [1, 3, 5]);

// Add page range as string
await merger.add('./document.pdf', '1-3');

// Add mixed ranges and individual pages
await merger.add('./document.pdf', '1,3-5,7');

// Add pages using "to" syntax
await merger.add('./document.pdf', '2 to 6');

// Add from URL
await merger.add('https://example.com/file.pdf', '1-2');

// Add from Buffer
const buffer = fs.readFileSync('./document.pdf');
await merger.add(buffer);
```

--------------------------------

### Add pages to PDF

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/types.md

Demonstrates various ways to specify pages when adding a PDF, using 1-indexed page numbers.

```javascript
// Add all pages
await merger.add(pdf, undefined);   // or null, or no second argument

// Single page
await merger.add(pdf, 2);

// Multiple as array
await merger.add(pdf, [1, 3, 5]);

// Range as string
await merger.add(pdf, '1-3');

// Complex string
await merger.add(pdf, '1,3-5,7');

// String array
await merger.add(pdf, ['1', '2', '5']);
```

--------------------------------

### Internal Usage in PDFMerger.add()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

Demonstrates how the function is used internally when passing a string to the add method.

```javascript
import PDFMerger from 'pdf-merger-js';

const merger = new PDFMerger();

// These all use parsePagesString internally:
await merger.add('file.pdf', '1-3');          // Parsed: [1, 2, 3]
await merger.add('file.pdf', '1,3-5,7');      // Parsed: [1, 3, 4, 5, 7]
await merger.add('file.pdf', '2 to 6');       // Parsed: [2, 3, 4, 5, 6]
```

--------------------------------

### Add PDF Pages

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Browser.md

Add pages from various sources like Files, Blobs, URLs, or Uint8Arrays. Pages are 1-indexed.

```javascript
import PDFMerger from 'pdf-merger-js/browser';

const merger = new PDFMerger();

// Add from File input element
const fileInput = document.querySelector('input[type="file"]');
const file = fileInput.files[0];
await merger.add(file);

// Add multiple pages from file
await merger.add(file, '1-3');

// Add from Blob (e.g., from fetch)
const response = await fetch('https://example.com/document.pdf');
const blob = await response.blob();
await merger.add(blob);

// Add from URL string
await merger.add('https://example.com/file.pdf', [1, 2]);

// Add from URL object
const url = new URL('https://example.com/file.pdf');
await merger.add(url);

// Add from Uint8Array
const bytes = new Uint8Array([...]);
await merger.add(bytes);
```

--------------------------------

### Handle Promise<Uint8Array> in browser

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/types.md

Retrieves a PDF as a Uint8Array instance in a browser environment.

```javascript
const uint8 = await merger.saveAsBuffer();
// uint8 is Uint8Array instance
// Can be sent to server, converted to Blob, etc.
```

--------------------------------

### Catching Node.js Input Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Demonstrates how to catch and identify input errors in Node.js using error message matching.

```javascript
try {
  await merger.add('./missing.pdf');
} catch (error) {
  if (error.message.includes('neither a valid file-path nor a valid URL')) {
    console.error('Input file or URL not found');
  }
}
```

--------------------------------

### Add pages from source document

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMergerBase.md

Loads a source PDF and copies specified pages into the current merged document using pdf-lib.

```javascript
async _addPagesFromDocument(input: PdfInput, pages?: number[]): Promise<void>
```

--------------------------------

### Internal PDF Load Options

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/configuration.md

Hardcoded configuration for loading PDFs, enabling the merging of encrypted files without passwords.

```javascript
{
  ignoreEncryption: true
}
```

--------------------------------

### Handle Browser File Input

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Process files selected via an HTML input element and export as a Blob.

```javascript
import PDFMerger from 'pdf-merger-js/browser';

const merger = new PDFMerger();
const fileInput = document.querySelector('input[type="file"]');

for (const file of fileInput.files) {
  await merger.add(file);
}

const blob = await merger.saveAsBlob();
const url = URL.createObjectURL(blob);
// Use for preview or download
```

--------------------------------

### Import for TypeScript

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/configuration.md

Import the appropriate module based on the environment to utilize automatic type definitions.

```typescript
import PDFMerger from 'pdf-merger-js';
// Types from: index.d.ts
```

```typescript
import PDFMerger from 'pdf-merger-js/browser';
// Types from: browser.d.ts
```

--------------------------------

### URL and Mixed Inputs

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Merge remote PDF files via HTTP(S) URLs or combine them with local files.

```bash
pdf-merge -o merged.pdf https://example.com/file.pdf
pdf-merge -o merged.pdf 'https://example.com/file.pdf#1-3'
```

```bash
pdf-merge -o merged.pdf ./local.pdf 'https://example.com/remote.pdf#1-2'
```

--------------------------------

### Basic PDF Merging

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Merge multiple local PDF files into a single output file.

```bash
pdf-merge -o merged.pdf file1.pdf file2.pdf
pdf-merge -o merged.pdf ./documents/a.pdf ./documents/b.pdf
```

--------------------------------

### Handle Invalid Input File Error

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Triggered when a specified input file does not exist.

```bash
$ pdf-merge -o output.pdf nonexistent.pdf
An error occurred while merging the PDFs: [Error details]
```

--------------------------------

### Merge PDFs in the Browser

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Import from the browser-specific entry point to handle file inputs and export merged PDFs as Blobs.

```javascript
import PDFMerger from 'pdf-merger-js/browser';

const merger = new PDFMerger();
const file = document.querySelector('input[type="file"]').files[0];
await merger.add(file);
const blob = await merger.saveAsBlob();
```

--------------------------------

### Handle Promise<Blob> in browser

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/types.md

Retrieves a PDF as a Blob object in a browser environment.

```javascript
const blob = await merger.saveAsBlob();
// blob is Blob with MIME type 'application/pdf'
// Can be downloaded, previewed, or uploaded
```

--------------------------------

### Parse Multiple Pages

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

Pages can be listed in any order. Duplicates are preserved.

```javascript
parsePagesString('1,2,3')       // [1, 2, 3]
parsePagesString(' 1, 2, 3 ')   // [1, 2, 3]
parsePagesString('2,4,6')       // [2, 4, 6]
```

--------------------------------

### Merge from URLs

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Add remote PDF files directly via URL.

```javascript
const merger = new PDFMerger();
await merger.add('https://example.com/file1.pdf');
await merger.add('https://example.com/file2.pdf', '1-3');
await merger.save('merged.pdf');
```

--------------------------------

### Handle Promise<void> return

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/types.md

Shows the result of methods that perform async operations without returning data.

```javascript
const result = await merger.add('file.pdf');  // result is undefined
```

--------------------------------

### Parse Page Selection

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Logic for extracting file paths and page ranges from input strings.

```javascript
const [filePath, pagesString] = inputFile.split('#')
const pages = pagesString ? parsePagesString(pagesString) : null
await merger.add(filePath, pages)
```

--------------------------------

### Implement General Error Handling Pattern

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Use a try-catch block to handle various error types during PDF merging operations.

```javascript
import PDFMerger from 'pdf-merger-js';

const merger = new PDFMerger();

try {
  await merger.add('./input1.pdf');
  await merger.add('./input2.pdf', '1-3');
  await merger.setMetadata({ title: 'Merged PDF' });
  await merger.save('./output.pdf');
} catch (error) {
  // Handle different error types
  if (error.message.includes('Invalid parameter')) {
    console.error('Invalid input parameters:', error.message);
  } else if (error.message.includes('not a valid')) {
    console.error('Invalid file or URL:', error.message);
  } else if (error.message.includes('EACCES')) {
    console.error('Permission denied:', error.message);
  } else {
    console.error('Unexpected error:', error.message);
  }
}
```

--------------------------------

### Define Type Definitions

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Reference types for input sources, metadata, and page selection patterns.

```typescript
Uint8Array | ArrayBuffer | Blob | URL | Buffer | string | PathLike
```

```typescript
Uint8Array | ArrayBuffer | Blob | URL | File | string
```

```typescript
{
  producer?: string;
  author?: string;
  title?: string;
  creator?: string;
}
```

```typescript
string | string[] | number | number[] | undefined | null
```

--------------------------------

### Merge PDFs in Node.js

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Use the default export from the main entry point to merge local PDF files and save the result to the filesystem.

```javascript
import PDFMerger from 'pdf-merger-js';

const merger = new PDFMerger();
await merger.add('./file1.pdf');
await merger.add('./file2.pdf', '1-3');
await merger.save('./output.pdf');
```

--------------------------------

### Handle Invalid Page Selection Error

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Triggered when the page selection string format is incorrect.

```bash
$ pdf-merge -o output.pdf 'input.pdf#invalid'
An error occurred while merging the PDFs: Invalid parameter "pages". Must be a string like "1,2,3" or "1-3" or an Array of numbers.
```

--------------------------------

### save()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Browser.md

Downloads the merged PDF directly in the browser.

```APIDOC
## save(fileName)

### Description
Downloads the merged PDF directly in the browser. Triggers a download dialog and automatically appends .pdf extension.

### Parameters
- **fileName** (string) - Required - Base filename without extension.

### Returns
- **Promise<void>**
```

--------------------------------

### Perform Basic Merge

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Combine multiple PDF files into a single document.

```javascript
import PDFMerger from 'pdf-merger-js';

const merger = new PDFMerger();
await merger.add('doc1.pdf');
await merger.add('doc2.pdf');
await merger.save('merged.pdf');
```

--------------------------------

### Merge PDFs via Node.js Child Process

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Execute the CLI tool programmatically from a Node.js environment using child_process.

```javascript
import { execFile } from 'child_process';
import { promisify } from 'util';

const execFileAsync = promisify(execFile);

async function mergePDFsViaCLI(inputFiles, outputPath) {
  try {
    const { stdout } = await execFileAsync('pdf-merge', [
      '--output', outputPath,
      ...inputFiles
    ]);
    console.log(stdout);
  } catch (error) {
    console.error('Merge failed:', error.stderr);
    throw error;
  }
}

await mergePDFsViaCLI(['a.pdf#1-3', 'b.pdf#5'], 'output.pdf');
```

--------------------------------

### Handle Empty Document Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Catch errors when attempting to save a PDF document that contains no pages.

```javascript
const merger = new PDFMerger();
// No pages added
try {
  const buffer = await merger.saveAsBuffer();
  // May fail depending on pdf-lib version
} catch (error) {
  console.error('Cannot save empty document');
}
```

--------------------------------

### Catching Browser Input Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Demonstrates how to catch and identify URL validation errors in the browser.

```javascript
try {
  await merger.add('not a url');
} catch (error) {
  if (error.message.includes('not a valid url')) {
    console.error('URL format is invalid');
  }
}
```

--------------------------------

### Handle Missing Output Flag Error

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Triggered when the --output flag is omitted during execution.

```bash
$ pdf-merge input1.pdf input2.pdf
Please provide an output file using the --output flag
```

--------------------------------

### saveAsBuffer() / saveAsBlob()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Exports the merged PDF as a binary format.

```APIDOC
## saveAsBuffer() / saveAsBlob()

### Description
Exports the merged PDF as a binary buffer (Node.js) or a Blob (Browser).
```

--------------------------------

### Catching Input Type Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Demonstrates how to catch and identify input type errors using the error message string.

```javascript
try {
  await merger.add(someUnknownObject);
} catch (error) {
  if (error.message.includes('pdf-input must be of type')) {
    console.error('Input type not supported');
  }
}
```

--------------------------------

### Parse Single Pages

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

Parses a single page number. Whitespace is ignored.

```javascript
parsePagesString('2')    // [2]
parsePagesString(' 2 ')  // [2] (whitespace trimmed)
```

--------------------------------

### add()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Browser.md

Adds pages from a PDF document to the merged output.

```APIDOC
## add(input, pages)

### Description
Adds pages from a PDF document to the merged output. Pages are appended to the end of the current document.

### Parameters
- **input** (PdfInput) - Required - PDF source: File, Blob, URL string, Uint8Array, ArrayBuffer, or URL object.
- **pages** (string | string[] | number | number[] | undefined | null) - Optional - Pages to add. If undefined, adds all pages. 1-indexed.

### Returns
- **Promise<void>**
```

--------------------------------

### Serve PDF via HTTP Response

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Export the merged PDF as a buffer for direct transmission in a Node.js HTTP response.

```javascript
import PDFMerger from 'pdf-merger-js';

const merger = new PDFMerger();
await merger.add('doc1.pdf');
await merger.add('doc2.pdf');

const buffer = await merger.saveAsBuffer();

response.setHeader('Content-Type', 'application/pdf');
response.setHeader('Content-Disposition', 'attachment; filename=merged.pdf');
response.end(buffer);
```

--------------------------------

### Handle PDF Merger Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Use standard try-catch blocks to handle file path errors or invalid page selection parameters.

```javascript
try {
  await merger.add('./missing.pdf');
} catch (error) {
  if (error.message.includes('neither a valid file-path')) {
    console.error('File not found or invalid URL');
  } else if (error.message.includes('Invalid parameter')) {
    console.error('Invalid page selection format');
  } else {
    console.error('Unknown error:', error.message);
  }
}
```

--------------------------------

### Handle File System Write Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Catch specific Node.js file system errors like permission issues or missing directories during the save process.

```javascript
try {
  await merger.save('/read-only-dir/output.pdf');
} catch (error) {
  if (error.code === 'EACCES') {
    console.error('Permission denied');
  } else if (error.code === 'ENOENT') {
    console.error('Directory does not exist');
  }
}
```

--------------------------------

### Merge Multiple Page Ranges

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Combine non-contiguous pages from several source documents.

```bash
pdf-merge -o report.pdf \
  'section1.pdf#1-5' \
  'section2.pdf#3,7,9-11' \
  'appendix.pdf#1-2'
```

--------------------------------

### Parse Ranges with 'to' Keyword

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

Alternative range syntax using the 'to' keyword, which is case-insensitive.

```javascript
parsePagesString('1to3')      // [1, 2, 3]
parsePagesString(' 1to3 ')    // [1, 2, 3]
parsePagesString(' 1 to 3 ')  // [1, 2, 3]
parsePagesString('2 to 6')    // [2, 3, 4, 5, 6]
```

--------------------------------

### Merge PDFs via CLI

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Execute the pdf-merge command to combine specific pages from multiple PDF files into a single output file.

```bash
pdf-merge --output merged.pdf 'file1.pdf#1-3' 'file2.pdf#5-7'
```

--------------------------------

### Function Signature

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

The function accepts a string and returns an array of numbers.

```javascript
function parsePagesString(pages: string): number[]
```

--------------------------------

### Clear memory with reset()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/configuration.md

Call reset() on a merger instance to clear memory after saving a document, allowing the instance to be reused for subsequent merges.

```javascript
const merger = new PDFMerger();

// Merge 1
await merger.add('file1.pdf');
await merger.save('output1.pdf');

// Clear memory
merger.reset();

// Merge 2
await merger.add('file2.pdf');
await merger.save('output2.pdf');
```

--------------------------------

### reset()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMergerBase.md

Clears the internal PDF document state, allowing the merger instance to be reused.

```APIDOC
## reset()

### Description
Clears the internal PDF document state, discarding all accumulated pages and metadata.

### Returns
- **void**
```

--------------------------------

### Detect Global Environment

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/configuration.md

Used internally to identify the execution environment, supporting modern environments, browsers, and web workers.

```javascript
const globalObject =
  typeof globalThis === 'object'
    ? globalThis           // Modern environments
    : typeof window === 'object'
      ? window             // Browser
      : typeof self === 'object'
        ? self             // Web Worker
        : this
```

--------------------------------

### Handle Errors in Browser Context

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Manage errors specifically when working with file inputs and blobs in a browser environment.

```javascript
import PDFMerger from 'pdf-merger-js/browser';

const merger = new PDFMerger();

try {
  const fileInput = document.querySelector('input[type="file"]');
  for (const file of fileInput.files) {
    await merger.add(file);
  }
  const blob = await merger.saveAsBlob();
  downloadBlob(blob, 'merged.pdf');
} catch (error) {
  if (error.message.includes('not a valid url')) {
    console.error('URL error:', error.message);
  } else {
    showErrorMessage(error.message);
  }
}
```

--------------------------------

### PDFMerger.add(pdf, pages)

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/types.md

Adds a PDF file to the merger. The pages parameter accepts various formats to specify which pages to include.

```APIDOC
## PDFMerger.add(pdf, pages)

### Description
Adds a PDF file to the merger instance. Page numbers are 1-indexed.

### Parameters
- **pdf** (string | Buffer | Uint8Array | ArrayBuffer) - Required - The PDF source file.
- **pages** (string | string[] | number | number[] | undefined | null) - Optional - Specifies which pages to include. Defaults to all pages if undefined or null.
```

--------------------------------

### Run in Silent Mode

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Suppresses standard output, useful for automation scripts.

```bash
pdf-merge -s -o merged.pdf input1.pdf input2.pdf
# No output unless an error occurs
```

--------------------------------

### Metadata Interface Definition

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMergerBase.md

Defines the structure for PDF metadata, where all fields are optional.

```javascript
interface Metadata {
  producer?: string
  author?: string
  title?: string
  creator?: string
}
```

--------------------------------

### Serialize document to Base64

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMergerBase.md

Serializes the internal document to a Base64 data URI, primarily used for browser-based download functionality.

```javascript
async _saveAsBase64(): Promise<string>
```

--------------------------------

### Merge Selective Pages

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Specify page ranges or individual pages to include from source files.

```javascript
const merger = new PDFMerger();
await merger.add('file1.pdf', '1-5');      // Pages 1-5
await merger.add('file2.pdf', [3, 7, 9]);  // Pages 3, 7, 9
await merger.add('file3.pdf', '1-2,5');    // Pages 1, 2, 5
await merger.save('output.pdf');
```

--------------------------------

### Merge with Complex Page Selection

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Merge specific page ranges from multiple files.

```bash
pdf-merge -o merged.pdf 'file1.pdf#1-2' 'file2.pdf#1,2,5-7'
```

--------------------------------

### save()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Node.md

Saves the merged PDF to the file system and resets the internal document state.

```APIDOC
## save(fileName)

### Description
Saves the merged PDF to the file system and resets the internal document state. The file is written synchronously to the specified path.

### Parameters
- **fileName** (string | PathLike) - Required - Output file path. Can be relative or absolute.

### Return Type
- **Promise<void>**
```

--------------------------------

### Convert input to Uint8Array

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMergerBase.md

Converts various input formats like Uint8Array, ArrayBuffer, Blob, or URL into a Uint8Array. Subclasses provide additional support for file paths or File objects.

```javascript
async _getInputAsUint8Array(input: PdfInput): Promise<Uint8Array>
```

--------------------------------

### add(input, pages)

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMergerBase.md

Adds pages from a source PDF to the merged document. Supports various page selection formats including single pages, arrays, and ranges.

```APIDOC
## add(input, pages)

### Description
Adds pages from a source PDF to the merged document. The method handles page selection parsing and delegates to internal page addition logic.

### Parameters
- **input** (PdfInput) - Required - PDF source (type varies by implementation)
- **pages** (string | string[] | number | number[] | undefined | null) - Optional - Page selection specification (e.g., 'all', '1-3', [1, 3])

### Returns
- **Promise<void>**
```

--------------------------------

### Silent Mode for Scripts

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Execute merge without console output, suitable for automated workflows.

```bash
pdf-merge -s -o output.pdf input1.pdf input2.pdf
if [ $? -eq 0 ]; then
  echo "Merge successful"
else
  echo "Merge failed"
fi
```

--------------------------------

### Export as Buffer

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Browser.md

Retrieve the merged PDF as a Uint8Array for server uploads or local blob creation.

```javascript
import PDFMerger from 'pdf-merger-js/browser';

const merger = new PDFMerger();
const fileInput = document.querySelector('input[type="file"]');

for (const file of fileInput.files) {
  await merger.add(file);
}

const buffer = await merger.saveAsBuffer();

// Upload to server
const formData = new FormData();
formData.append('pdf', new Blob([buffer], { type: 'application/pdf' }));
await fetch('/api/upload', { method: 'POST', body: formData });

// Or create preview blob
const blob = new Blob([buffer], { type: 'application/pdf' });
const url = URL.createObjectURL(blob);
```

--------------------------------

### Catching PDFMerger.add() Validation Errors

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/errors.md

Pattern for identifying and handling specific page parameter validation errors.

```javascript
try {
  await merger.add(pdf, 'invalid');
} catch (error) {
  if (error.message.includes('Invalid parameter "pages"')) {
    console.error('Page selection format is invalid');
  }
}
```

--------------------------------

### save(fileName)

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/README.md

Saves or downloads the merged PDF.

```APIDOC
## save(fileName)

### Description
Finalizes the merge and saves the result as a file (Node.js) or triggers a browser download.
```

--------------------------------

### Set PDF Metadata

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Browser.md

Apply custom metadata fields like author or title to the merged document before saving.

```javascript
const merger = new PDFMerger();

const fileInput = document.querySelector('input[type="file"]');
for (const file of fileInput.files) {
  await merger.add(file);
}

await merger.setMetadata({
  producer: 'My PDF Application',
  author: 'Web User',
  title: 'Merged Report'
});

const blob = await merger.saveAsBlob();
```

--------------------------------

### Merge PDFs via Shell Script

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/cli.md

Automate PDF merging by invoking the CLI directly from a bash script.

```bash
#!/bin/bash

INPUT_DIR="./pdfs"
OUTPUT_FILE="merged.pdf"

# Merge all PDFs in directory, extracting first 5 pages from each
pdf-merge -o "$OUTPUT_FILE" \
  "$INPUT_DIR/doc1.pdf#1-5" \
  "$INPUT_DIR/doc2.pdf#1-5" \
  "$INPUT_DIR/doc3.pdf#1-5"

if [ $? -eq 0 ]; then
  echo "✓ Merge complete: $OUTPUT_FILE"
else
  echo "✗ Merge failed"
  exit 1
fi
```

--------------------------------

### parsePagesString(pages)

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/parsePagesString.md

Parses a string specification of pages into an array of integers. Supports comma-separated values, hyphens, and 'to' keywords for ranges.

```APIDOC
## parsePagesString(pages)

### Description
Parses a string input representing page numbers or ranges into an array of integers. The function validates the input string against a specific format before parsing.

### Parameters
- **pages** (string) - Required - A string representing pages, such as "1,2,3", "1-3", or "1to3".

### Usage Example
```javascript
import { parsePagesString } from 'pdf-merger-js';

const pages = parsePagesString('1,5-7,10');
console.log(pages); // [1, 5, 6, 7, 10]
```

### Validation Rules
- Only positive integers are allowed.
- Ranges can be specified using hyphens (-) or the "to" keyword.
- Multiple items must be separated by commas (,).
- Spaces around numbers and operators are automatically trimmed.
- Empty strings, negative numbers, decimals, and special characters will result in an error.
```

--------------------------------

### reset()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Browser.md

Resets the internal document state, discarding all accumulated pages and metadata.

```APIDOC
## reset()

### Description
Resets the internal document state, discarding all accumulated pages and metadata. Allows reuse of the same PDFMerger instance for a new merge operation.

### Signature
`reset(): void`

### Returns
- **void**
```

--------------------------------

### Save Merged PDF

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Browser.md

Trigger a browser download of the merged PDF. The .pdf extension is automatically appended to the provided filename.

```javascript
import PDFMerger from 'pdf-merger-js/browser';

const merger = new PDFMerger();
const files = document.querySelector('input[type="file"]').files;

for (const file of files) {
  await merger.add(file);
}

// Download with automatic .pdf extension
// Prompts user to save as "merged.pdf"
await merger.save('merged');

// Resulting file: "merged.pdf"
```

--------------------------------

### saveAsBuffer()

Source: https://github.com/nbesli/pdf-merger-js/blob/master/_autodocs/api-reference/PDFMerger-Node.md

Exports the merged PDF as a Node.js Buffer without writing to disk.

```APIDOC
## saveAsBuffer()

### Description
Exports the merged PDF as a Node.js Buffer without writing to disk. Useful for streaming, API responses, or further processing.

### Return Type
- **Promise<Buffer>** - Node.js Buffer containing the complete PDF binary
```