Lean vs VeriFast
| Lean | VeriFast | |
|---|---|---|
| Free plan | Yes | No |
| Free trial | No | No |
| Paid from | Free | — |
| Open source | No | No |
| Platforms | Linux, macOS, Web, Windows | Windows, macOS, Linux |
| Verification method | deductive | symbolic |
| Supported formalisms | theorem-proving | contracts |
| Proof artifacts | Yes | — |
| Input languages | Lean 4 | C, Rust, Java |
| Deployment | both | self-hosted |
Both are listed in Best Formal Verification Tools. On The Geeks Club, Lean scores higher on our published basis.