Best Formal Verification Tools in 2026
31 formal verification tools ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
31ranked
18free plans on this page
3 Oct 2026last checked
#1 PVS Top pick · 8.8 Free plan · Free
#2 Rocq Runner-up · 8.7 Free plan · Free #3 ACL2 Also great · 8.7 Free plan · Free
- Free plan LinuxmacOSWindows
- Free plan
- Yes
- Verification method
- hybrid
- Supported formalisms
- theorem-proving
- Counterexamples
- Yes
- Proof artifacts
- Yes
RecognisedDocumentedFree planFree trialPlatformsFree About PVSVisit site - Free plan extensionLinuxmacOSWebWindows
- Free plan
- Yes
- Verification method
- deductive
- Supported formalisms
- theorem-proving
- Proof artifacts
- Yes
RecognisedDocumentedFree planFree trialPlatformsFree About RocqVisit site - Free plan LinuxmacOSself-hostedWindows
- Free plan
- Yes
- Verification method
- deductive
- Supported formalisms
- theorem-proving
- Counterexamples
- Yes
- Proof artifacts
- Yes
RecognisedDocumentedFree planFree trialPlatformsFree About ACL2Visit site - Free plan LinuxmacOSself-hostedWindows
- Free plan
- Yes
- Verification method
- deductive
- Supported formalisms
- theorem-proving
- Counterexamples
- Yes
- Proof artifacts
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan AndroidapiLinuxmacOSself-hostedWebWindows
- Free plan
- Yes
- Supported formalisms
- theorem-proving
- Counterexamples
- Yes
- Proof artifacts
- Yes
RecognisedDocumentedFree planFree trialPlatformsFree About Z3Visit site - Free plan WindowsmacOSLinux
- Free plan
- Yes
- Verification method
- hybrid
- Supported formalisms
- contracts
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan WindowsmacOSLinux
- Free plan
- Yes
- Verification method
- deductive
- Supported formalisms
- contracts
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan LinuxmacOS
- Free plan
- Yes
- Verification method
- hybrid
- Supported formalisms
- theorem-proving
RecognisedDocumentedFree planFree trialPlatforms - Free plan LinuxmacOSWindows
- Free plan
- Yes
- Verification method
- model-checking
- Supported formalisms
- temporal-logic
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatformsFree About SPINVisit site - WebWindowsmacOSLinux
- Verification method
- deductive
- Supported formalisms
- theorem-proving
- Proof artifacts
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan WindowsmacOSLinux
- Free plan
- Yes
- Verification method
- model-checking
- Supported formalisms
- contracts
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatformsFree About CBMCVisit site - WebLinuxWindows
- Verification method
- deductive
- Supported formalisms
- contracts
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan WindowsmacOSLinux
- Free plan
- Yes
- Verification method
- symbolic
- Supported formalisms
- temporal-logic
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan WindowsmacOSLinux
- Free plan
- Yes
- Verification method
- hybrid
- Supported formalisms
- temporal-logic
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan WindowsmacOSLinux
- Free plan
- Yes
- Verification method
- model-checking
- Supported formalisms
- invariants
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - WindowsmacOSLinux
- Verification method
- hybrid
- Supported formalisms
- invariants
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan WindowsmacOSLinux
- Free plan
- Yes
- Verification method
- model-checking
- Supported formalisms
- invariants
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan WindowsmacOSLinux
- Free plan
- Yes
- Verification method
- deductive
- Supported formalisms
- contracts
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - WebWindowsmacOSLinux
- Supported formalisms
- theorem-proving
- Proof artifacts
- Yes
RecognisedDocumentedFree planFree trialPlatforms - WindowsmacOSLinux
- Verification method
- hybrid
- Supported formalisms
- invariants
- Counterexamples
- Yes
- Proof artifacts
- Yes
RecognisedDocumentedFree planFree trialPlatforms - WindowsLinuxmacOS
- Verification method
- hybrid
- Supported formalisms
- theorem-proving
RecognisedDocumentedFree planFree trialPlatforms - Free plan WindowsLinux
- Free plan
- Yes
- Supported formalisms
- theorem-proving
- Counterexamples
- Yes
- Proof artifacts
- Yes
RecognisedDocumentedFree planFree trialPlatformsFree About HOL4Visit site - Free plan WebWindowsmacOSLinux
- Free plan
- Yes
- Verification method
- deductive
- Supported formalisms
- theorem-proving
RecognisedDocumentedFree planFree trialPlatforms - WindowsmacOSLinux
- Free plan
- Yes
- Verification method
- hybrid
- Supported formalisms
- contracts
- Counterexamples
- Yes
RecognisedDocumentedFree planFree trialPlatforms - Free plan WebWindowsLinux
- Free plan
- Yes
- Verification method
- model-checking
RecognisedDocumentedFree planFree trialPlatforms
Is your platform on this list?
Numbered spots on this list can be sponsored. They are labelled, and the editorial order and scores never change for payment.
Questions about this list
Which formal verification tool is ranked first on The Geeks Club?
PVS is ranked #1 of 31 with a score of 8.8. Rocq is second and ACL2 third.
How many of these have a free plan?
18 of the 25 on this page publish a free plan on their own pricing pages.
How is this list ranked?
Ranked on how quickly a newcomer can get going: documentation depth, a free tier or trial, and the platforms it runs on. Paid placements never change a rank.
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