# Redirect Checker - HTTP Redirect Chain Analyzer

[![Deployed on Cloudflare Workers](https://img.shields.io/badge/Deployed-Cloudflare%20Workers-F38020?logo=cloudflare)](https://redirect-checker.autocompany.workers.dev)
[![TypeScript](https://img.shields.io/badge/TypeScript-5.x-3178C6?logo=typescript)](https://www.typescriptlang.org/)
[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)

> **Analyze HTTP redirect chains, detect redirect loops, and measure performance.**
> Free online tool for SEO professionals, DevOps engineers, and developers.

**Try it now:** [redirect-checker.autocompany.workers.dev](https://redirect-checker.autocompany.workers.dev)

## Features

- **Complete redirect chain tracing** - Follow 301, 302, 307, 308 redirects
- **Redirect loop detection** - Automatically identify circular redirects
- **Multiple User-Agent presets** - Test as Googlebot, Bingbot, Mobile, curl
- **Response time measurement** - Track latency at each hop
- **API-first design** - RESTful JSON API for integration
- **Edge computing** - Fast responses from Cloudflare's global network

## Quick Start

### Web Interface

Visit [redirect-checker.autocompany.workers.dev](https://redirect-checker.autocompany.workers.dev) and enter any URL.

### API

```bash
curl "https://redirect-checker.autocompany.workers.dev/api/check?url=https://bit.ly/example"
```

**Response:**

```json
{
  "status": "success",
  "input_url": "https://bit.ly/example",
  "final_url": "https://example.com/page",
  "redirect_count": 2,
  "total_time_ms": 342,
  "chain": [
    {
      "url": "https://bit.ly/example",
      "status": 301,
      "location": "https://intermediate.com",
      "time_ms": 120
    },
    {
      "url": "https://intermediate.com",
      "status": 302,
      "location": "https://example.com/page",
      "time_ms": 98
    },
    {
      "url": "https://example.com/page",
      "status": 200,
      "time_ms": 124
    }
  ],
  "meta": {
    "checked_at": "2026-02-18T10:23:45.000Z",
    "user_agent": "RedirectChecker/1.0"
  }
}
```

## Use Cases

### For SEO Professionals

- **Verify 301 redirects** - Ensure permanent redirects are correctly configured
- **Detect redirect chains** - Find multi-hop redirects diluting link equity
- **Check Googlebot experience** - Test redirects as search engine crawlers
- **Audit site migrations** - Verify redirects after domain or URL changes

### For Developers

- **Debug URL routing** - Understand where redirects are happening
- **Detect redirect loops** - Find infinite redirect cycles
- **Measure performance** - Track response times at each hop
- **Test shortened URLs** - Uncover final destinations

### For DevOps

- **Monitor redirect health** - Integrate with monitoring systems
- **Validate CDN configuration** - Verify edge redirects
- **Security auditing** - Trace suspicious URL patterns

## API Reference

### `GET /api/check`

Check the redirect chain for a URL.

**Parameters:**

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `url` | string | Yes | URL to check |
| `user_agent` | string | No | User-Agent preset |
| `max_redirects` | number | No | Max redirects (default: 20, max: 50) |
| `timeout` | number | No | Timeout in ms (default: 10000) |

**User-Agent Presets:**

| Preset | User-Agent |
|--------|------------|
| `default` | RedirectChecker/1.0 |
| `googlebot` | Mozilla/5.0 (compatible; Googlebot/2.1) |
| `bingbot` | Mozilla/5.0 (compatible; bingbot/2.0) |
| `mobile` | Mozilla/5.0 (iPhone; CPU iPhone OS 14_0) |
| `curl` | curl/7.68.0 |
| `apiclient` | API-Client/1.0 |

**Example - Check as Googlebot:**

```bash
curl "https://redirect-checker.autocompany.workers.dev/api/check?url=https://example.com&user_agent=googlebot"
```

### `GET /api/user-agents`

List all available User-Agent presets.

### `GET /health`

Health check endpoint.

## HTTP Redirect Types

| Status Code | Name | Description |
|-------------|------|-------------|
| 301 | Moved Permanently | Resource permanently moved |
| 302 | Found | Resource temporarily at different URL |
| 307 | Temporary Redirect | Temporary, preserve request method |
| 308 | Permanent Redirect | Permanent, preserve request method |

## Self-Hosting

Deploy your own instance on Cloudflare Workers:

```bash
# Clone the repository
git clone https://github.com/brancogao/redirect-checker.git
cd redirect-checker

# Install dependencies
npm install

# Run tests
npm test

# Deploy to Cloudflare Workers
npm run deploy
```

### Local Development

```bash
# Run local development server
npm run dev

# Open http://localhost:8788
```

## Tech Stack

- **Runtime:** Cloudflare Workers
- **Language:** TypeScript
- **Test Framework:** Vitest with Workers pool
- **Deployment:** Wrangler CLI

## Related Projects

- [Webhook Debugger](https://github.com/brancogao/webhook-debugger) - Inspect and debug webhooks with signature verification

## Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

## License

This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.

---

**Keywords:** redirect checker, http redirect analyzer, url redirect checker, 301 redirect checker, redirect chain checker, redirect loop detector, seo redirect tool, check redirect chain

**Links:** [Demo](https://redirect-checker.autocompany.workers.dev) · [GitHub](https://github.com/brancogao/redirect-checker) · [API](https://redirect-checker.autocompany.workers.dev/api/check)