Free and open first
Best Formal Verification Tools in 2026 — page 2
- 34 apps
- Research read 23 Sept 2026
- How the order is worked out
- 26
Z3
Free plan AndroidAPILinux+4Z3 offers a no-cost, MIT-licensed solver with SMT-LIB2 input, proof artifacts, counterexamples, and numerous language interfaces. Building it requires Python, and some APIs need additional toolchains.
- 27
UPPAAL
Free plan LinuxMacWindowsUPPAAL offers modeling, verification and statistical analysis for timed-automata systems, with related tools for additional analysis areas.
- 28
Stainless
Free plan LinuxMacWindowsStainless provides contract-based verification and counterexamples for modern Scala projects, with several installation and solver choices.
- 29
Ultimate Automizer
Free plan LinuxWebWindowsPick Ultimate Automizer if you need a free model checker for verifying C programs and want a web interface or Windows and Linux command-line releases.
- 30
Prusti
Free plan LinuxMacWindows - 31
Romeo
Free plan - 32
Satisfiability.jl
Free plan - 33
SeaHorn
Paid LinuxMacSelf-hostedChoose SeaHorn for research-oriented verification of C and other LLVM-based programs, especially when its model-checking and invariant-analysis components fit your workflow.
- 34
Viper
Paid ExtensionLinuxMac+2Viper provides a focused, open-source environment for permission-based program verification with several language entry points.