Best F* Alternatives in 2026
Updated
20 apps from formal verification tools ranked against F* on the same published basis.
- 1F* vs Z3
- 2F* vs Rocq
- 3F* vs Isabelle
- 4F* vs PVS
- 5F* vs ACL2
- 6F* vs Frama-C
- 7F* vs CBMC
- 8F* vs SPIN
- 9F* vs Lean
- 10F* vs Why3
- 11F* vs UPPAAL
- 12F* vs TLA+
- 13F* vs Alloy Analyzer
- 14F* vs K Framework
- 15F* vs Dafny
- 16F* vs cvc5
- 17F* vs CPAchecker
- 19F* vs PRISM
- 20F* vs NuSMV
- 21F* vs Stainless
F* alternatives compared
| # | App | Score | Free plan | From | Runs on |
|---|---|---|---|---|---|
| 1 | Z3 | 8.9 | Free plan | Free | Android, API, Linux, Mac, self-hosted, Web, Windows |
| 2 | Rocq | 8.2 | Free plan | Free | Browser, Linux, Mac, Web, Windows |
| 3 | Isabelle | 8.1 | Free plan | Free | Linux, Mac, self-hosted, Windows |
| 4 | PVS | 8.1 | Free plan | Free | Linux, Mac, Windows |
| 5 | ACL2 | 7.4 | No | — | Linux, Mac, self-hosted, Windows |
| 6 | Frama-C | 7.2 | No | — | Linux, Mac, Windows |
| 7 | CBMC | 7.1 | Free plan | Free | Linux, Mac, self-hosted, Windows |
| 8 | SPIN | 7.0 | Free plan | Free | Linux, Mac, Windows |
| 9 | Lean | 6.9 | No | — | Web, Windows, Mac, Linux |
| 10 | Why3 | 6.8 | No | — | Web, Linux, Windows |
| 11 | UPPAAL | 6.8 | Free plan | Free | Linux, Mac, Windows |
| 12 | TLA+ | 6.7 | No | — | Windows, Mac, Linux |
| 13 | Alloy Analyzer | 6.7 | Free plan | Free | API, Linux, Mac, Windows |
| 14 | K Framework | 6.6 | No | — | Linux, Mac |
| 15 | Dafny | 6.5 | No | — | Linux, Mac, self-hosted, Windows |
| 16 | cvc5 | 6.3 | No | — | Web, Windows, Mac, Linux |
| 17 | CPAchecker | 6.3 | No | — | Windows, Mac, Linux |
| 19 | PRISM | 6.0 | No | — | Windows, Mac, Linux |
| 20 | NuSMV | 5.9 | No | — | Windows, Mac, Linux |
| 21 | Stainless | 5.7 | No | — | Windows, Mac, Linux |
Make your app an alternative to F*
See the priceThe sponsored alternative slot on this page is labelled Sponsored.
Questions about F* alternatives
What is the best alternative to F*?
Z3, number 1 in formal verification tools with a score of 8.9 out of 10. The others here: Rocq, Isabelle, PVS and 16 more.
What is the best free alternative to F*?
Z3 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 mobile-first: a phone app alongside the web or desktop product, a free tier and the depth of its documentation.