Z3Prover/z3
{ "createdAt": "2015-03-26T18:16:07Z", "defaultBranch": "master", "description": "The Z3 Theorem Prover", "fullName": "Z3Prover/z3", "homepage": null, "language": "C++", "name": "z3", "pushedAt": "2025-11-26T02:08:17Z", "stargazersCount": 11572, "topics": [], "updatedAt": "2025-11-26T02:08:24Z", "url": "https://github.com/Z3Prover/z3"}Z3 is a theorem prover from Microsoft Research. It is licensed under the [MIT license]!(LICENSE.txt). Windows binary distributions include C++ runtime redistributables
If you are not familiar with Z3, you can start here.
Pre-built binaries for stable and nightly releases are available here.
Z3 can be built using [Visual Studio][1], a [Makefile][2], using [CMake][3], using [vcpkg][4], or using [Bazel][5]. It provides [bindings for several programming languages][6].
See the [release notes]!(RELEASE_NOTES.md) for notes on various stable releases of Z3.
![Try the online Z3 Guide]!(z3guide.jpeg)
Build status
Section titled “Build status”| Azure Pipelines | Open Bugs | Android Build | WASM Build | Windows Build | Pyodide Build | OCaml Build |
|---|---|---|---|---|---|---|
[1] !: #building-z3-on-windows-using-visual-studio-command-prompt [2] !: #building-z3-using-make-and-gccclang [3] !: #building-z3-using-cmake [4] !: #building-z3-using-vcpkg [5] !: #building-z3-using-bazel [6] !: #z3-bindings
Building Z3 on Windows using Visual Studio Command Prompt
Section titled “Building Z3 on Windows using Visual Studio Command Prompt”For 32-bit builds, start with:
python scripts/mk_make.pyor instead, for a 64-bit build:
python scripts/mk_make.py -xthen run:
cd buildnmakeZ3 uses C++20. The recommended version of Visual Studio is therefore VS2019 or later.
Security Features (MSVC): When building with Visual Studio/MSVC, a couple of security features are enabled by default for Z3:
- Control Flow Guard (
/guard:cf) - enabled by default to detect attempts to compromise your code by preventing calls to locations other than function entry points, making it more difficult for attackers to execute arbitrary code through control flow redirection - Address Space Layout Randomization (
/DYNAMICBASE) - enabled by default for memory layout randomization, required by the/GUARD:CFlinker option - These can be disabled using
python scripts/mk_make.py --no-guardcf(Python build) orcmake -DZ3_ENABLE_CFG=OFF(CMake build) if needed
Building Z3 using make and GCC/Clang
Section titled “Building Z3 using make and GCC/Clang”Execute:
python scripts/mk_make.pycd buildmakesudo make installNote by default g++ is used as C++ compiler if it is available. If you
prefer to use Clang, change the mk_make.py invocation to:
CXX=clang++ CC=clang python scripts/mk_make.pyNote that Clang < 3.7 does not support OpenMP.
You can also build Z3 for Windows using Cygwin and the Mingw-w64 cross-compiler. In that case, make sure to use Cygwin’s own Python and not some Windows installation of Python.
For a 64-bit build (from Cygwin64), configure Z3’s sources with
CXX=x86_64-w64-mingw32-g++ CC=x86_64-w64-mingw32-gcc AR=x86_64-w64-mingw32-ar python scripts/mk_make.pyA 32-bit build should work similarly (but is untested); the same is true for 32/64 bit builds from within Cygwin32.
By default, it will install z3 executables at PREFIX/bin, libraries at
PREFIX/lib, and include files at PREFIX/include, where the PREFIX
installation prefix is inferred by the mk_make.py script. It is usually
/usr for most Linux distros, and /usr/local for FreeBSD and macOS. Use
the --prefix= command-line option to change the install prefix. For example:
python scripts/mk_make.py --prefix=/home/leocd buildmakemake installTo uninstall Z3, use
sudo make uninstallTo clean Z3, you can delete the build directory and run the mk_make.py script again.
Building Z3 using CMake
Section titled “Building Z3 using CMake”Z3 has a build system using CMake. Read the [README-CMake.md]!(README-CMake.md) file for details. It is recommended for most build tasks, except for building OCaml bindings.
Building Z3 using vcpkg
Section titled “Building Z3 using vcpkg”vcpkg is a full platform package manager. To install Z3 with vcpkg, execute:
git clone https://github.com/microsoft/vcpkg.git./bootstrap-vcpkg.bat # For powershell./bootstrap-vcpkg.sh # For bash./vcpkg install z3Building Z3 using Bazel
Section titled “Building Z3 using Bazel”Z3 can be built using Bazel. This is known to work on Ubuntu with Clang (but may work elsewhere with other compilers):
bazel build //...Dependencies
Section titled “Dependencies”Z3 itself has only few dependencies. It uses C++ runtime libraries, including pthreads for multi-threading. It is optionally possible to use GMP for multi-precision integers, but Z3 contains its own self-contained multi-precision functionality. Python is required to build Z3. Building Java, .NET, OCaml and Julia APIs requires installing relevant toolchains.
Z3 bindings
Section titled “Z3 bindings”Z3 has bindings for various programming languages.
You can install a NuGet package for the latest release Z3 from nuget.org.
Use the --dotnet command line flag with mk_make.py to enable building these.
See [examples/dotnet]!(examples/dotnet) for examples.
These are always enabled.
See [examples/c]!(examples/c) for examples.
These are always enabled.
See [examples/c++]!(examples/c++) for examples.
Use the --java command line flag with mk_make.py to enable building these.
See [examples/java]!(examples/java) for examples.
Use the --ml command line flag with mk_make.py to enable building these.
See [examples/ml]!(examples/ml) for examples.
Python
Section titled “Python”You can install the Python wrapper for Z3 for the latest release from pypi using the command:
pip install z3-solverUse the --python command line flag with mk_make.py to enable building these.
Note that it is required on certain platforms that the Python package directory
(site-packages on most distributions and dist-packages on Debian-based
distributions) live under the install prefix. If you use a non-standard prefix
you can use the --pypkgdir option to change the Python package directory
used for installation. For example:
python scripts/mk_make.py --prefix=/home/leo --python --pypkgdir=/home/leo/lib/python-2.7/site-packagesIf you do need to install to a non-standard prefix, a better approach is to use
a Python virtual environment
and install Z3 there. Python packages also work for Python3.
Under Windows, recall to build inside the Visual C++ native command build environment.
Note that the build/python/z3 directory should be accessible from where Python is used with Z3
and it requires libz3.dll to be in the path.
virtualenv venvsource venv/bin/activatepython scripts/mk_make.py --pythoncd buildmakemake install# You will find Z3 and the Python bindings installed in the virtual environmentvenv/bin/z3 -h...python -c 'import z3; print(z3.get_version_string())'...See [examples/python]!(examples/python) for examples.
The Julia package Z3.jl wraps the C API of Z3. A previous version of it wrapped the C++ API: Information about updating and building the Julia bindings can be found in [src/api/julia]!(src/api/julia).
WebAssembly / TypeScript / JavaScript
Section titled “WebAssembly / TypeScript / JavaScript”A WebAssembly build with associated TypeScript typings is published on npm as z3-solver. Information about building these bindings can be found in [src/api/js]!(src/api/js).
Smalltalk (Pharo / Smalltalk/X)
Section titled “Smalltalk (Pharo / Smalltalk/X)”Project MachineArithmetic provides a Smalltalk interface to Z3’s C API. For more information, see MachineArithmetic/README.md.
System Overview
Section titled “System Overview”
Interfaces
Section titled “Interfaces”-
Default input format is SMTLIB2
-
Other native foreign function interfaces:
-
Python API (also available in pydoc format)
-
C
-
OCaml
-
Smalltalk (supports Pharo and Smalltalk/X)
Power Tools
Section titled “Power Tools”- The Axiom Profiler currently developed by ETH Zurich