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https://github.com/jshields-ca/pdf-accessibility

A comprehensive web application for evaluating PDF accessibility and automatically remediating common issues according to WCAG AA and AAA standards.
https://github.com/jshields-ca/pdf-accessibility

accessibility accessibility-automation accessibility-checker accessibility-testing pdf pdf-accessibility

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A comprehensive web application for evaluating PDF accessibility and automatically remediating common issues according to WCAG AA and AAA standards.

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README 

          
# PDF Accessibility Tool



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[![License](https://img.shields.io/github/license/jshields-ca/pdf-accessibility)](LICENSE)

[![Version](https://img.shields.io/github/package-json/v/jshields-ca/pdf-accessibility)](package.json)

[![Issues](https://img.shields.io/github/issues/jshields-ca/pdf-accessibility)](https://github.com/jshields-ca/pdf-accessibility/issues)

[![Pull Requests](https://img.shields.io/github/issues-pr/jshields-ca/pdf-accessibility)](https://github.com/jshields-ca/pdf-accessibility/pulls)

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A comprehensive web application for evaluating PDF accessibility and automatically remediating common issues according to WCAG AA and AAA standards.



---



**Author:** Jeremy Shields



---



## Project Status



[![Project Status: Active – Maintained and supported](https://img.shields.io/badge/status-active-brightgreen.svg)](https://github.com/jeremyshields/pdf-accessibility)



- **Current version:** 0.0.1 (initial/alpha release)

- This project is actively maintained. Contributions, bug reports, and feature requests are welcome!

- Expect rapid changes and improvements as the project matures.



---



## Features



- 🔍 **Automated PDF Analysis** - Comprehensive accessibility evaluation

- ♿ **WCAG Compliance** - Support for both AA and AAA standards

- 🔧 **Automatic Remediation** - Fix common issues without user intervention

- 📊 **Detailed Reports** - HTML reports with actionable insights

- 🎯 **Zero User Input** - Fully automated remediation process

- 🚀 **Modern Web Interface** - Beautiful, accessible user experience

- 📱 **Responsive Design** - Works on desktop, tablet, and mobile

- 🔒 **Security First** - File cleanup, rate limiting, and validation



## Supported Standards



- **WCAG 2.1 AA** - Standard compliance level required by most accessibility regulations

- **WCAG 2.1 AAA** - Enhanced accessibility with stricter requirements

- **PDF/UA** - PDF Universal Accessibility standards compatibility



## What Gets Fixed Automatically



### ✅ Automatic Fixes

- Missing document metadata (title, subject, language)

- Basic document structure and tagging

- Reading order optimization

- Form field accessibility attributes

- Document outline/bookmarks creation

- Language specification



### ⚠️ Manual Review Required

- Alternative text for images (requires human context)

- Color contrast verification

- Complex table structures

- Context-specific content descriptions



## Installation



### Prerequisites



- Node.js 16+ and npm

- Python 3.8+ (for PDF processing)

- Git



### Quick Start



1. **Clone the repository**

   ```bash

   git clone 

   cd pdf-accessibility-app

   ```

2. **Install Node.js dependencies**

   ```bash

   npm install

   ```

3. **Install Python dependencies**

   ```bash

   pip install -r requirements.txt

   ```

4. **Configure environment**

   ```bash

   cp .env.example .env

   # Edit .env with your settings

   ```

5. **Start the application**

   ```bash

   npm start

   ```

6. **Access the application**

   - Open http://localhost:3000 in your browser



## Development



### Development Mode

```bash

npm run dev

```



### Build for Production

```bash

npm run build

```



## API Endpoints



### Upload and Analyze PDF

```http

POST /api/analyze

Content-Type: multipart/form-data



Parameters:

- pdf: PDF file (max 50MB)

- wcagLevel: "AA" or "AAA"

```



### Remediate PDF

```http

POST /api/remediate/:jobId

Content-Type: application/json



Body:

{

  "autoFix": true

}

```



### Download Remediated PDF

```http

GET /api/download/:jobId

```



### Get Job Status

```http

GET /api/status/:jobId

```



## Architecture



```

pdf-accessibility-app/

├── server.js                 # Express server

├── package.json              # Node.js dependencies

├── requirements.txt          # Python dependencies

├── public/                   # Frontend files

│   ├── index.html           # Main HTML

│   ├── styles.css           # CSS styles

│   └── app.js               # Frontend JavaScript

├── src/

│   └── services/            # Backend services

│       ├── PDFProcessor.js          # PDF processing

│       ├── AccessibilityAnalyzer.js # WCAG analysis

│       ├── RemediationService.js    # Auto-remediation

│       └── ReportGenerator.js       # HTML reports

├── uploads/                 # Temporary PDF storage

├── output/                  # Remediated PDFs

└── reports/                 # Generated reports

```



## Configuration



### Environment Variables



Create a `.env` file based on `.env.example`:



```env

PORT=3000

MAX_FILE_SIZE=52428800

RATE_LIMIT_MAX_REQUESTS=100

FILE_RETENTION_HOURS=24

```



### Security Settings



- **File Upload**: 50MB maximum, PDF files only

- **Rate Limiting**: 100 requests per 15 minutes per IP

- **File Cleanup**: Automatic deletion after 24 hours

- **CORS**: Configurable allowed origins

- **CSP**: Content Security Policy headers



## Usage



### Web Interface



1. **Upload PDF**: Drag and drop or select a PDF file

2. **Choose Standard**: Select WCAG AA or AAA compliance level

3. **Analyze**: Wait for automatic analysis to complete

4. **View Report**: Review detailed accessibility findings

5. **Remediate**: Click to automatically fix issues

6. **Download**: Get the improved, accessible PDF



### Programmatic Usage



```javascript

// Upload and analyze

const formData = new FormData();

formData.append('pdf', pdfFile);

formData.append('wcagLevel', 'AA');



const response = await fetch('/api/analyze', {

  method: 'POST',

  body: formData

});

const result = await response.json();



// Remediate

const remediationResponse = await fetch(`/api/remediate/${result.jobId}`, {

  method: 'POST',

  headers: { 'Content-Type': 'application/json' },

  body: JSON.stringify({ autoFix: true })

});

```



## Accessibility Checks



### WCAG AA Compliance

- 1.1.1 Non-text Content

- 1.3.1 Info and Relationships

- 1.3.2 Meaningful Sequence

- 1.4.3 Contrast (Minimum)

- 2.4.2 Page Titled

- 2.4.5 Multiple Ways

- 3.1.1 Language of Page

- 4.1.2 Name, Role, Value



### WCAG AAA Additional Checks

- 1.4.6 Contrast (Enhanced)

- 3.3.5 Help

- 2.4.9 Link Purpose (Link Only)

- 2.4.10 Section Headings



## Performance



- **File Processing**: Optimized for PDFs up to 50MB

- **Concurrent Jobs**: Multiple users supported simultaneously

- **Memory Management**: Automatic cleanup and garbage collection

- **Caching**: Temporary file caching for better performance



## Security



- **Input Validation**: File type and size validation

- **Rate Limiting**: Prevents abuse and DoS attacks

- **File Cleanup**: Automatic deletion of temporary files

- **Secure Headers**: Helmet.js security headers

- **CORS Protection**: Configurable cross-origin policies



## Monitoring



### Health Check

```http

GET /health

```



### Logs

Application logs are written to:

- Console (development)

- File: `./logs/app.log` (production)



## Deployment



### Production Setup



1. **Environment Configuration**

   ```bash

   NODE_ENV=production

   PORT=80

   ```

2. **Process Management**

   ```bash

   # Using PM2

   npm install -g pm2

   pm2 start server.js --name pdf-accessibility-tool

   ```

3. **Reverse Proxy**

   Configure nginx or Apache to proxy requests to the Node.js server.



### Docker Deployment



```dockerfile

# Example Dockerfile

FROM node:16-alpine

WORKDIR /app

COPY package*.json ./

RUN npm ci --only=production

COPY . .

EXPOSE 3000

CMD ["npm", "start"]

```



## Browser Support



- Chrome 80+

- Firefox 75+

- Safari 13+

- Edge 80+



## How to Contribute



1. Fork the repository

2. Create a feature branch: `git checkout -b feature-name`

3. Make your changes

4. Run tests and lint: `npm test && npm run lint`

5. Commit using `npx cz` for conventional commits

6. Push: `git push origin feature-name`

7. Create a Pull Request



## Community & Support



- [Open an issue](https://github.com/jeremyshields/pdf-accessibility/issues) for bugs or feature requests

- [Discussions](https://github.com/jeremyshields/pdf-accessibility/discussions) for Q&A and ideas

- [Changelog](CHANGELOG.md) for release history



## License



MIT License - see [LICENSE](LICENSE) for details.



---



Built with ❤️ for universal accessibility by Jeremy Shields.