API development & testing Category leader
Insomnia
API client and design tool with local, Git and cloud storage
Key features
- Automated API tests
- OpenAPI design
- Mock servers
Our picks · 6 tools reviewed
Best API development & testing software for 2026
Helps developers design, document, test and mock APIs. Below: the names buyers expect to see, the newer tools gaining ground, and how their key features and prices compare. How we pick; nobody pays for a place here.
| Feature |
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|---|---|---|---|---|---|---|
| Pricing | Free plan $12/user/mo | Free plan $9/mo | Contact sales | Free plan $9/user/mo | Free plan $6/user/mo | Free plan $79/user/year |
| Best for | — | — | — | — | Developer teams of 5 to 200 that want a free, local-first Postman alternative whose API collections live in Git alongside the code. | Solo developers and small teams under 20 who want a local, Git-synced API client without a required cloud account. |
| Team size | 1–500+ people | 1–500+ people | 51–500+ people | 1–500 people | 1–500+ people | 1–500 people |
| Request builder | Not listed | Yes | Not listed | Yes | Yes | Yes |
| Automated API tests | Yes | Yes | Not listed | Yes | Yes | Not listed |
| OpenAPI design | Yes | Not listed | Yes | Yes | Not listed | Not listed |
| Mock servers | Yes | Yes | Yes | Yes | Yes | Not listed |
| Shared collections | Not listed | Yes | Not listed | Yes | Yes | Not listed |
| Generated documentation | Not listed | Yes | Yes | Yes | Yes | Not listed |
| Visit | Visit | Visit | Visit | Visit | Visit | Visit |
Category leaders
The best-known API development & testing tools: the ones most buyers shortlist.
API development & testing Category leader
Postman
API platform for building, testing and documenting APIs together
Key features
- Request builder
- Automated API tests
- Mock servers
- Shared collections
- Generated documentation
API development & testing Category leader
SwaggerHub
Design, document and govern OpenAPI and AsyncAPI definitions
Key features
- OpenAPI design
- Mock servers
- Generated documentation
Rising picks
Newer tools with real traction and a clear difference from the leaders.
API development & testing Rising
Apidog
API design, debugging, testing, mocking and docs in one app
Key features
- Request builder
- Automated API tests
- OpenAPI design
- Mock servers
- Shared collections
- Generated documentation
API development & testing Rising
Bruno
Open-source, local-first API client that stores collections in Git
Key features
- Request builder
- Automated API tests
- Mock servers
- Shared collections
- Generated documentation
API development & testing Rising
Yaak
Local-first desktop API client for REST, GraphQL and gRPC
Key features
- Request builder