expo-pdf-text-extract

Native PDF text extraction for React Native and Expo. Extract text content from PDF files using platform-native APIs - no OCR needed for digital PDFs.

Features

• Native Performance - Uses PDFKit (iOS) and PDFBox (Android) for fast, reliable extraction
• No OCR Required - Extracts embedded text directly from digital PDFs
• Expo Compatible - Works with Expo development builds (SDK 49+)
• TypeScript Support - Full type definitions included
• Simple API - Just one function to extract text
• Page-level Control - Extract from specific pages or get page count
• Multiple Path Formats - Supports file://, content://, and absolute paths

When to Use This

| Scenario | This Package | Alternative | |----------|-------------|-------------| | Digital PDFs (from email, downloads) | Yes | - | | Scanned PDFs (images of paper) | No | Use OCR library | | Need text content only | Yes | - | | Need to render/view PDF | No | Use react-native-pdf | | Expo Go | No | Requires dev build |

Requirements

• Expo SDK: 49.0.0 or higher
• React Native: 0.72.0 or higher
• iOS: 15.1 or higher
• Android: API 21 (Lollipop) or higher

Important: This package requires an Expo development build. It will not work in Expo Go.

Installation

Using Expo

npx expo install expo-pdf-text-extract

Using npm/yarn

npm install expo-pdf-text-extract
# or
yarn add expo-pdf-text-extract

Create Development Build

Since this is a native module, you need to create a development build:

# For iOS
npx expo run:ios

# For Android
npx expo run:android

# Or create a development build
eas build --profile development --platform all

Quick Start

import { extractText, isAvailable } from 'expo-pdf-text-extract';

// Check if native module is available
if (isAvailable()) {
  // Extract text from a PDF file
  const text = await extractText('/path/to/document.pdf');
  console.log(text);
}

API Reference

isAvailable()

Check if the native PDF extractor is available.

function isAvailable(): boolean

Returns false when:

• Running in Expo Go
• Native module failed to load
• Platform not supported

Example:

import { isAvailable } from 'expo-pdf-text-extract';

if (isAvailable()) {
  // Show PDF upload option
} else {
  // Show message: "PDF extraction requires a development build"
}

extractText(filePath)

Extract all text from a PDF file.

function extractText(filePath: string): Promise<string>

Parameters:

• filePath - Path to the PDF file. Supports:
  • file:///path/to/file.pdf - File URI
  • /absolute/path/to/file.pdf - Absolute path
  • content://... - Content URI (Android document picker)

Returns: Promise resolving to extracted text

Throws:

• Error if native module not available
• Error if file not found
• Error if PDF is invalid or corrupted

Example:

import { extractText } from 'expo-pdf-text-extract';
import * as DocumentPicker from 'expo-document-picker';

// Pick a PDF file
const result = await DocumentPicker.getDocumentAsync({
  type: 'application/pdf',
});

if (!result.canceled) {
  const text = await extractText(result.assets[0].uri);
  console.log('Extracted text:', text);
}

getPageCount(filePath)

Get the number of pages in a PDF.

function getPageCount(filePath: string): Promise<number>

Example:

import { getPageCount } from 'expo-pdf-text-extract';

const pages = await getPageCount('/path/to/document.pdf');
console.log(`PDF has ${pages} pages`);

extractTextFromPage(filePath, pageNumber)

Extract text from a specific page.

function extractTextFromPage(filePath: string, pageNumber: number): Promise<string>

Parameters:

• filePath - Path to the PDF file
• pageNumber - Page number (1-indexed, first page is 1)

Example:

import { extractTextFromPage, getPageCount } from 'expo-pdf-text-extract';

// Extract text from first page only
const firstPageText = await extractTextFromPage('/path/to/document.pdf', 1);

// Extract text from each page separately
const pageCount = await getPageCount('/path/to/document.pdf');
for (let i = 1; i <= pageCount; i++) {
  const pageText = await extractTextFromPage('/path/to/document.pdf', i);
  console.log(`Page ${i}:`, pageText);
}

extractTextWithInfo(filePath)

Extract text with additional metadata.

function extractTextWithInfo(filePath: string): Promise<{
  text: string;
  pageCount: number;
  success: boolean;
  error?: string;
}>

Example:

import { extractTextWithInfo } from 'expo-pdf-text-extract';

const result = await extractTextWithInfo('/path/to/document.pdf');

if (result.success) {
  console.log(`Extracted ${result.text.length} characters from ${result.pageCount} pages`);
} else {
  console.error('Extraction failed:', result.error);
}

Usage with Document Picker

import { extractText, isAvailable } from 'expo-pdf-text-extract';
import * as DocumentPicker from 'expo-document-picker';

async function handlePdfUpload() {
  // Check if extraction is available
  if (!isAvailable()) {
    Alert.alert(
      'Not Available',
      'PDF extraction requires a development build. Please rebuild the app.'
    );
    return;
  }

  // Pick PDF file
  const result = await DocumentPicker.getDocumentAsync({
    type: 'application/pdf',
    copyToCacheDirectory: true,
  });

  if (result.canceled) {
    return;
  }

  try {
    // Extract text
    const text = await extractText(result.assets[0].uri);

    // Use the extracted text
    console.log('Extracted text:', text.substring(0, 500));

    // Parse the text, search for patterns, etc.
    const hasKeyword = text.includes('invoice');

  } catch (error) {
    Alert.alert('Error', `Failed to extract text: ${error.message}`);
  }
}

Error Handling

import { extractText, isAvailable } from 'expo-pdf-text-extract';

async function safeExtract(filePath: string): Promise<string | null> {
  // Check availability first
  if (!isAvailable()) {
    console.warn('PDF extraction not available');
    return null;
  }

  try {
    return await extractText(filePath);
  } catch (error) {
    if (error.message.includes('not found')) {
      console.error('File not found:', filePath);
    } else if (error.message.includes('PDF_LOAD_ERROR')) {
      console.error('Invalid or corrupted PDF');
    } else {
      console.error('Extraction failed:', error.message);
    }
    return null;
  }
}

Platform Differences

iOS (PDFKit)

• Uses Apple's native PDFKit framework
• Built into iOS, no additional dependencies
• Excellent support for standard PDF formats
• Minimum iOS version: 15.1

Android (PDFBox)

• Uses Apache PDFBox (Android port)
• Text is sorted by position on page for better readability
• Handles compressed PDF streams (FlateDecode, etc.)
• Minimum API level: 21

Troubleshooting

"PDF extraction is not available"

This error occurs when running in Expo Go. Solution:

# Create a development build
npx expo run:ios
# or
npx expo run:android

Empty text returned

If extractText() returns empty string:

1. Scanned PDF - The PDF contains images, not text. Use OCR instead.
2. Protected PDF - The PDF has copy protection. Text extraction may be blocked.
3. Corrupted PDF - Try opening the PDF in another app to verify it's valid.

Slow extraction on large PDFs

For PDFs with many pages, consider:

1. Extract page by page using extractTextFromPage()
2. Show progress indicator to users
3. Process in background using a worker

Performance

| PDF Size | Pages | Extraction Time (approx) | |----------|-------|--------------------------| | Small | 1-5 | < 100ms | | Medium | 10-50 | 100-500ms | | Large | 100+ | 500ms-2s |

Times measured on iPhone 13 and Pixel 6

Contributing

Contributions are welcome! Please read our contributing guidelines before submitting PRs.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

License

MIT License - see LICENSE for details.

Credits

• iOS implementation uses Apple's PDFKit
• Android implementation uses PDFBox-Android by Tom Roush

Related Packages

• expo-document-picker - Pick documents from device
• react-native-pdf - Display PDFs (viewing, not extraction)
• pdf-lib - Create and modify PDFs in JavaScript