Skip to content
SPECIFICTION
Get listed

Cython

cython.org

Free plan WindowsmacOSLinux
Visit cython.org
Spec score 7.9 #12 of 28 in Code Transpilers

What it is

Cython is a free compiler for Python and the extended Cython language, used to create C extensions for Python. It translates source code into C or C++ that can be built as Python extension modules. Optional static type declarations can help produce more efficient C, while declared C and C++ types let Python code call existing C or C++ code. Cython supports source-level debugging across Python, Cython and C, and the project describes uses including wrapping external libraries, embedding CPython in applications and speeding up Python code with C modules. It can work with multidimensional NumPy arrays and integrate with low-level libraries and applications. Installation is available through pip, and some scientific Python distributions bundle it. A C compiler is required, with installation guidance for Linux, macOS and Windows. The project describes compatibility with major C and C++ compilers for CPython 3.8 and later, and characterizes PyPy support as mostly usable. Limited API and free-threading CPython support in Cython 3.1 are experimental. Cython is available under the Apache 2.0 License.

Spec sheet

What it does
Cython is an optimising static compiler for Python and the extended Cython language, used to write C extensions for Python.Read 30 Sep 2026 · cython.org
Build requirement
Cython requires a C compiler; the installation guide gives compiler guidance for Linux, macOS and Windows.Read 30 Sep 2026 · docs.cython.org
C and C++
Cython lets Python code call C or C++ code and supports declaring C or C++ types.Read 30 Sep 2026 · cython.org
Data and libraries
The project describes using Cython with multidimensional NumPy arrays and integrating with existing low-level libraries and applications.Read 30 Sep 2026 · cython.org
Debugging
Cython supports combined source-level debugging across Python, Cython and C code.Read 30 Sep 2026 · cython.org
Experimental support
The homepage says support for the CPython Limited API and free-threading CPython is available in Cython 3.1 but considered experimental.Read 30 Sep 2026 · cython.org
Generated code
Cython translates source code into C or C++ code that can be compiled as Python extension modules.Read 30 Sep 2026 · docs.cython.org
Installation
The documentation recommends installing Cython with pip and says some scientific Python distributions, including Anaconda and Sage, bundle it.Read 30 Sep 2026 · docs.cython.org
Intended use
The project identifies wrapping external C libraries, embedding CPython in existing applications and speeding up Python code with fast C modules as use cases.Read 30 Sep 2026 · cython.org
Python compatibility
The homepage says generated code compiles with major C and C++ compilers for CPython 3.8 and later, and describes PyPy support as mostly usable.Read 30 Sep 2026 · cython.org
Static typing
Optional static type declarations can help generate more efficient C code from Python-like code.Read 30 Sep 2026 · docs.cython.org
Support channels
The homepage directs users with questions to the Cython users mailing list and links a separate core developer mailing list.Read 30 Sep 2026 · cython.org

Plans and prices

Cython Free Freely available under the open source Apache 2.0 License Read 30 Sep 2026 · cython.org

Every Cython plan and price →

Strong points and limits

Strong points

  • Translates Cython and Python source into C or C++.
  • Supports debugging across Python, Cython and C.
  • Works with multidimensional NumPy arrays.
  • Available under the Apache 2.0 License.

Limits

  • A C compiler is required.
  • Limited API and free-threading support are experimental.
  • PyPy support is described as mostly usable.

Who it suits

Cython suits Python developers building C extensions, wrapping external C libraries or embedding CPython in applications. It may also fit developers seeking faster Python code through C modules, provided they have a C compiler.

Verdict

Cython provides a path from Python-like code to compiled extension modules, with options for C and C++ integration. A C compiler is needed, and some newer compatibility support remains experimental.

Where Specifiction places it

Alternatives to CythonAll alternatives →