A minimalist, lightweight API testing desktop application built with Flutter. Designed for developers who need a fast, efficient alternative to traditional API testing tools with powerful automation capabilities.
Postboy API tester streamlines the API development workflow by providing essential testing features with a focus on speed and simplicity. No account creation, no cloud dependencies—just pure, local API testing power.
- Real-time Header Management: Add headers using intuitive key-value text fields with instant URL updates
- Flexible JSON Body Editing: Write JSON directly or build it using key-value pairs
- JSON Formatting: Clean up and format copied JSON with a single click
- Bearer Token Authentication: Streamlined JWT token support—the only auth method modern developers need
- Theme Support: Switch seamlessly between light and dark themes
Convert between key-value pairs and JSON format effortlessly. Build your request body the way that makes sense for your workflow.
Validate API responses with precision:
- Key Matching: Check if a specific key exists in the response (any value)
- Key-Value Matching: Verify exact key-value pairs in the response
- Multiple Conditions: Add unlimited key-value pairs for comprehensive validation
- Perfect for Testing: Quickly locate specific items in complex response structures
Run automated API tests without writing a single line of code:
- Configurable Iterations: Set custom run counters for stress testing
- Dynamic Data Generation:
- Random value generation with upper and lower bounds
- Incremental value generation for sequential testing
- Support for all data types (strings, numbers, booleans, etc.)
- Parameter Flexibility: Apply dynamic values to any body parameter
- Local Storage: All requests saved locally—no cloud, no accounts, no hassle
- Offline Ready: Test localhost endpoints without internet connectivity
- Privacy First: Your API data stays on your machine
Unlike heavyweight alternatives, Postboy focuses on what developers actually use daily:
- ⚡ Lightning Fast: No bloat, just essential features
- 🎯 Developer-Centric: Built by developers, for developers
- 🔒 Private & Secure: Complete offline functionality
- 🤖 Automation Made Easy: Visual automation setup without scripting
- 🎨 Clean Interface: Minimalist design that stays out of your way
- Download the latest release for your platform
- Launch the application
- Start testing your APIs immediately—no setup required
- Rapid API Development: Quick endpoint testing during development
- Response Validation: Verify API responses match expected structures
- Load Testing: Run automated requests to test API performance
- Sequential Testing: Test endpoints with incremental data patterns
- Local Development: Test localhost APIs without internet dependency
- Windows, macOS, or Linux
- No internet connection required for localhost testing
Built with Flutter for cross-platform compatibility and native performance. Used Dio for HTTP requests, Drift for local database and BLoC for state management.
This project is licensed under the MIT License - see the LICENSE file for details.
Contributions are welcome! Please feel free to submit issues or pull requests.
For bug reports or feature requests, please open an issue on the repository.
Built for developers who value simplicity, speed, and privacy.