Best Lean Alternatives in 2026
Updated
20 tools from formal verification tools ranked against Lean on the same published basis.
- 1Lean vs PVS
- 2Lean vs Rocq
- 3Lean vs Z3
- 4Lean vs Alloy Analyzer
- 5Lean vs UPPAAL
- 6Lean vs CBMC
- 7Lean vs Isabelle
- 8Lean vs SPIN
- 9Lean vs ACL2
- 10Lean vs Frama-C
- 11Lean vs Dafny
- 13Lean vs CPAchecker
- 14Lean vs HOL Light
- 15Lean vs Viper
- 16Lean vs cvc5
- 17Lean vs NuSMV
- 18Lean vs PRISM
- 19Lean vs Stainless
- 20Lean vs Boogie
- 21Lean vs OpenJML
Lean alternatives compared
| # | Tool | Score | Free plan | From | Runs on |
|---|---|---|---|---|---|
| 1 | PVS | 7.5 | Free plan | Free | Linux, Mac, Windows |
| 2 | Rocq | 7.5 | Free plan | Free | Browser, Linux, Mac, Web, Windows |
| 3 | Z3 | 7.4 | Free plan | Free | Android, API, Linux, Mac, self-hosted, Web, Windows |
| 4 | Alloy Analyzer | 7.2 | Free plan | Free | API, Linux, Mac, Windows |
| 5 | UPPAAL | 7.2 | Free plan | Free | Linux, Mac, Windows |
| 6 | CBMC | 7.1 | Free plan | Free | Linux, Mac, self-hosted, Windows |
| 7 | Isabelle | 7.1 | Free plan | Free | Linux, Mac, self-hosted, Windows |
| 8 | SPIN | 7.1 | Free plan | Free | Linux, Mac, Windows |
| 9 | ACL2 | 7.0 | No | — | Linux, Mac, self-hosted, Windows |
| 10 | Frama-C | 6.9 | No | — | Linux, Mac, Windows |
| 11 | Dafny | 6.8 | No | — | Linux, Mac, self-hosted, Windows |
| 13 | CPAchecker | 6.3 | No | — | Windows, Mac, Linux |
| 14 | HOL Light | 6.3 | No | — | Web, Windows, Mac, Linux |
| 15 | Viper | 6.3 | No | — | Windows, Mac, Linux |
| 16 | cvc5 | 6.2 | No | — | Web, Windows, Mac, Linux |
| 17 | NuSMV | 6.2 | No | — | Windows, Mac, Linux |
| 18 | PRISM | 6.2 | No | — | Windows, Mac, Linux |
| 19 | Stainless | 6.2 | No | — | Windows, Mac, Linux |
| 20 | Boogie | 6.1 | No | — | — |
| 21 | OpenJML | 6.1 | No | — | Windows, Mac, Linux |
Make your tool an alternative to Lean
See the priceThe sponsored alternative slot on this page is labelled Sponsored.
Questions about Lean alternatives
What is the best alternative to Lean?
PVS, number 1 in formal verification tools with a score of 7.5 out of 10. The others here: Rocq, Z3, Alloy Analyzer and 16 more.
What is the best free alternative to Lean?
PVS is the best-ranked alternative with a free plan. 8 of the 20 alternatives here publish a free plan on their own pricing pages.
How are these alternatives ranked?
Ranked on what each maker publishes, the fullest spec sheet first: how deeply the product is documented, the platforms it runs on, a free tier or trial to test it, and its standing.