JIT compiler

A just-in-time (JIT) compiler is a part of the runtime environment for Python that compiles bytecode into machine code at runtime. This approach contrasts with traditional ahead-of-time (AOT) compilation, which compiles the entire program before execution.

In CPython, the JIT compiler introduced in Python 3.13 through PEP 744 is still experimental and is disabled by default. To use it, you need to build CPython with the --enable-experimental-jit option.

By compiling code just in time, a JIT compiler can optimize the execution of your program based on the actual runtime context, potentially improving performance significantly.

Related Resources

Tutorial

Python 3.13: Free Threading and a JIT Compiler

Python 3.13 enhanced Python performance. Make a custom Python build with Docker to enable free threading and a JIT compiler. Learn how these features affect the language's ecosystem.

advanced python

For additional information on related topics, take a look at the following resources:

• PyPy: Faster Python With Minimal Effort (Tutorial)
• What's New in Python 3.13 (Course)
• Python 3.13: Free Threading and a JIT Compiler (Quiz)