VeriFast vs Viper
| VeriFast | Viper | |
|---|---|---|
| Free plan | No | No |
| Free trial | No | No |
| Paid from | — | — |
| Open source | No | No |
| Platforms | Windows, macOS, Linux | extension, Linux, macOS, Web, Windows |
| Verification method | symbolic | hybrid |
| Supported formalisms | contracts | contracts |
| Input languages | C, Rust, Java | Viper language; Go, Python, and Rust via front-end tools |
| Deployment | self-hosted | self-hosted |
| Free plan | — | Yes |
| Counterexamples | — | Yes |
Both are listed in Best Formal Verification Tools. On Inferse, Viper scores higher on our published basis.