CBMC

Free plan LinuxMacSelf-hostedWindows

What CBMC is

CBMC is a free bounded model checker for examining C and C++ programs. It explores execution paths and checks assertions, including array bounds, pointer safety, exceptions, user-defined assertions, and some undefined behavior such as signed integer overflow. Its method unwinds loops and sends the resulting equation to a decision procedure, so inputs may need a bounded size. The repository lists support for C89, C99, most of C11, C17, C23, many GCC and Visual Studio extensions, and SystemC through Scoot; listed input languages also include Java bytecode. CBMC supports contracts and can produce counterexamples. Its incremental SMT2 backend can use an SMT-LIB 2.6-compliant solver, with Z3 and CVC5 as examples. Distribution options include macOS Homebrew instructions, Ubuntu DEB packages, Windows MSI installers, and Docker images. The tool is licensed under the 4-clause BSD license. The guide describes use in routine development and continuous integration; released versions are intended for production use, unlike develop versions.

Who it suits

CBMC is for developers who need to check C or C++ program behavior and assertions, including in continuous integration. It suits teams able to work with bounded inputs and a supported solver or distribution.

What it does well

Checks bounds, pointer safety, and user assertions.
Can produce counterexamples.
Supports several C standards and extensions.
Available through installers and Docker images.
Licensed under the 4-clause BSD license.

What to know first

Analysis may require bounded inputs.
Develop versions are not recommended for production.
Uses loop unwinding before decision procedures.

Limits

CBMC performs bounded analysis, which may require restricting input sizes and unwinding loops. The free plan is the software under the 4-clause BSD license.

Plans

Plan	Billed and limits	Price
CBMC	4-clause BSD licensed open-source software	Free

As diffblue.github.io lists them, read 4 Oct 2026. The maker's own page has the final word.

Getting started

Visit the CBMC website for project information.
Choose a distribution route for Linux, macOS, Windows, or Docker.
Install a released version for production use.
Configure an SMT-LIB 2.6-compliant solver such as Z3 or CVC5 if using the incremental SMT2 backend.
Use goto-cc in Makefiles to collect project models for verification.

Verdict

CBMC provides a free route to bounded verification of C and C++ programs, with multiple distribution options and solver support. Its bounded analysis may require input limits, and the repository distinguishes production-intended releases from develop versions.

Questions

How much does CBMC cost?

The listed plan is free, and CBMC is licensed under the 4-clause BSD license.

Which platforms does CBMC support?

It is listed for Linux, macOS, Windows, and self-hosted deployment. Distribution options include Ubuntu DEB packages, macOS Homebrew instructions, Windows MSI installers, and Docker images.

Which programming languages can CBMC analyze?

The listed input languages are C, C++, Java bytecode, and SystemC. The repository describes support for multiple C standards and SystemC using Scoot.

Can CBMC provide counterexamples?

Yes. CBMC supports contracts and can produce counterexamples.

Which solvers can CBMC use?

Its incremental SMT2 backend can use an SMT-LIB 2.6-compliant solver; Z3 and CVC5 are given as examples.

How can users get help with problems?

The repository directs users who encounter problems to file a bug report as a GitHub issue.

Facts from CBMC's own pages

Bounded analysis: CBMC may require restricting inputs to a bounded size, and its verification unwinds loops before passing the resulting equation to a decision procedure. · diffblue.github.io, 4 Oct 2026
Build integration: goto-cc can replace gcc or cl.exe in Makefiles to collect project models for verification. · diffblue.github.io, 4 Oct 2026
Continuous integration: The user guide describes using CBMC as part of routine software development and continuous integration. · diffblue.github.io, 4 Oct 2026
Distribution: The release page provides macOS Homebrew instructions, Ubuntu DEB packages, Windows MSI installers, and Docker container images. · github.com, 4 Oct 2026
Language support: The repository states support for C89, C99, most of C11, C17, C23, many GCC and Visual Studio extensions, and SystemC using Scoot. · github.com, 4 Oct 2026
License: The repository identifies CBMC as licensed under the 4-clause BSD license. · github.com, 4 Oct 2026
Platforms: The installation guide points to installation instructions for macOS, Ubuntu, Windows, and Docker. · diffblue.github.io, 4 Oct 2026
Purpose: CBMC is a bounded model checker for C and C++ programs that explores possible execution paths and checks assertions. · diffblue.github.io, 4 Oct 2026
Related tools: The user guide names CBMC Viewer and CBMC Starter Kit as third-party tools for summarizing findings and adding verification to a project. · diffblue.github.io, 4 Oct 2026
Release guidance: The repository says released versions are tested and intended for production use, while develop versions are not recommended for production use. · github.com, 4 Oct 2026
Safety checks: It can check array bounds, pointer safety, exceptions, user-specified assertions, and some undefined behavior such as signed integer overflow. · github.com, 4 Oct 2026
Solver support: CBMC supports an incremental SMT2 backend that can use an SMT-LIB 2.6 compliant solver, with examples for Z3 and CVC5. · diffblue.github.io, 4 Oct 2026
Support: The repository asks users encountering problems to file a bug report as a GitHub issue. · github.com, 4 Oct 2026

Where CBMC stands on Freedom251

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