PyPy is a fast, compliant alternative implementation of the Python language (2.7.2). It has several advantages and distinct features:

  • Speed: thanks to its Just-in-Time compiler, Python programs often run faster on PyPy. (What is a JIT compiler?)
  • Memory usage: large, memory-hungry Python programs might end up taking less space than they do in CPython.
  • Compatibility: PyPy is highly compatible with existing python code. It supports ctypes and can run popular python libraries like twisted and django.
  • Sandboxing: PyPy provides the ability to run untrusted code in a fully secure way.
  • Stackless: PyPy comes by default with support for stackless mode, providing micro-threads for massive concurrency.
  • As well as other features.

Download and try out the PyPy release 1.8!

Want to know more? A good place to start is our detailed speed and compatibility reports! is neither affiliated with the authors of this page nor responsible for its contents. This is a safe-cache copy of the original web site.