API Contract Tester vs Stubborn Contract
| API Contract Tester | Stubborn Contract | |
|---|---|---|
| Free plan | Yes | Yes |
| Free trial | No | No |
| Paid from | $19/mo | Free |
| Open source | No | No |
| Platforms | Web | api, self-hosted |
| Free plan | Yes | Yes |
| Paid from | 19 /mo | — |
| Contract formats | TypeScript, OpenAPI, JSON | YAML, Groovy, Java, Kotlin |
| Self-hosted deployment | Yes | Yes |
| Consumer verification | — | Yes |
| Provider verification | — | Yes |
| Contract registry | — | Yes |
Both are listed in Best Contract Testing Tools. On Specifiction, API Contract Tester scores higher on our published basis.