Best API Testing and Development Tools
Postman, Insomnia, or something lighter? The right API tool for your development workflow.
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API development and testing tools are essential for any team building web or mobile applications. The right tool helps you design, test, document, and debug APIs efficiently. The market has evolved beyond Postman — here's our comparison of the top options.
1.Postman
The most popular API platform with testing, documentation, monitoring, and collaboration features. Used by 25+ million developers globally.
Pros
- Most comprehensive API platform
- Excellent collection organisation and sharing
- Built-in test scripting and automation
- API documentation generation
Cons
- Becoming bloated with too many features
- Account required — sync to Postman cloud
- Resource-heavy desktop app
- Pricing increased significantly
2.Bruno
Fast, open-source API client that stores collections as files in your Git repository. No account required, no cloud sync — files live with your code.
Pros
- Open source and free
- Git-friendly — collections are files
- No account or cloud sync required
- Fast and lightweight
Cons
- Smaller ecosystem than Postman
- Fewer automation and testing features
- Documentation still growing
- No built-in API monitoring
3.Insomnia
Clean, focused API client from Kong. Good balance between features and simplicity. Supports REST, GraphQL, and gRPC.
Pros
- Clean, focused interface
- Good GraphQL and gRPC support
- Plugin system for extensions
- Open-source core
Cons
- Kong acquisition led to account requirements
- Community trust issues after sync changes
- Fewer features than Postman
- Plugin ecosystem is small
4.Thunder Client (VS Code)
Lightweight API client that runs inside VS Code. Perfect for developers who want API testing without leaving their editor.
Pros
- Runs inside VS Code — no separate app
- Lightweight and fast
- Free for core features
- Collections support for organising requests
Cons
- Limited to VS Code users
- Fewer features than standalone tools
- Collection sharing requires paid plan
- No CLI for CI/CD integration
Build vs Buy
Use existing API testing tools — there's no reason to build custom ones. For most teams: start with Thunder Client (free, in VS Code) or Bruno (free, Git-friendly) for individual use. Adopt Postman when you need team collaboration, API documentation, or monitoring. The free tiers of these tools cover most team needs.
Frequently Asked Questions
Yes, but it depends on your needs. Postman is the most feature-rich option for API testing, documentation, and team collaboration. However, if you find it bloated or dislike the account requirement, Bruno (open-source, Git-based) and Thunder Client (VS Code) are excellent alternatives for individual developers.
Postman for teams needing collaboration, shared collections, and API documentation. Bruno for teams that prefer Git-based collaboration (collections as files alongside code). Thunder Client for solo developers or small teams happy working within VS Code. Choose based on how your team already collaborates.
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