HTTP Toolkit
Intercept, debug & mock HTTP with one click
About HTTP Toolkit
HTTP Toolkit is an open-source tool for intercepting, debugging, testing, and building with HTTP(S). It offers one-click interception for browsers, mobile apps, Docker containers, and backend processes across Windows, macOS, and Linux.
Pros & Cons
Pros
- Beautiful, modern UI that's much easier to use than older alternatives like Fiddler or Charles
- One-click interception works across browsers, mobile apps, Docker, and backend languages
- Fully open-source with a generous free tier covering most common use cases
- Cross-platform support for Windows, macOS, and Linux
- Built-in API documentation and validation for thousands of APIs
- Active development with frequent updates and community contributions
Cons
- Advanced features like automated rewriting require a paid subscription
- Fewer features than mature enterprise tools like Burp Suite for security testing
- Limited built-in performance and load testing capabilities
- Relatively newer tool with a smaller community compared to established alternatives
Key Features
One-Click Traffic Interception
Capture HTTP(S) traffic from browsers, Android/iOS apps, Docker containers, and backend processes with zero configuration
Request & Response Inspection
Examine URLs, status codes, headers, and bodies with built-in content-type parsing and MDN documentation for standard headers
Traffic Rewriting & Breakpoints
Manually rewrite intercepted requests and responses using breakpoints, or set up automated rewriting rules
Built-in HTTP Client
Send custom requests directly to explore and test APIs with full control over headers, body, and parameters
Mock Responses & Error Simulation
Define static responses, map to local files, or simulate errors and timeouts to test client behavior
HAR Import/Export
Import and export traffic as HAR files or generate ready-to-use code snippets for 20+ tools and languages
API Validation & Documentation
Built-in validation and docs for 2,600+ APIs, plus support for custom OpenAPI specifications
Advanced TLS & Proxy Configuration
Configure TLS passthrough, proxy ports, client certificates, whitelisted certificates, and upstream proxies
Pricing
- Intercept all supported clients
- Inspect and debug raw HTTP data
- Filter, delete & pin requests
- Manual request/response breakpoints
- Built-in HTTP client
- Everything in Hobbyist
- Automated HTTP mocking & rewriting
- Traffic redirection & mock responses
- HAR import/export & code generation
- Compression & caching analysis
- API validation for 2600+ APIs
- TLS passthrough & proxy config
- 25% savings on annual billing
- Everything in Professional
- Centralized team billing
- Transferable team licenses
- Team workspaces (coming soon)
- Custom licensing & bulk discounts
- Private support & training
Best For
API Debugging & Development
Inspect and modify HTTP traffic to debug API integrations, test edge cases, and validate request/response formats
Mobile App Testing
Intercept traffic from Android and iOS apps to debug API calls, test error handling, and verify data flow
Mock Server Simulation
Create mock responses for APIs that don't exist yet or simulate errors to test client resilience
Docker & Microservice Debugging
Capture and analyze HTTP traffic between Docker containers and microservices to diagnose communication issues
Security & Privacy Auditing
Inspect outgoing HTTP requests from applications to verify what data is being sent and to whom
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