JAX vs Pythran in 2026
JAX, Pythran and PyOverdrive compared on what each does, licence and price facts, install steps and what to check before choosing one for NumPy code.
SayDeploy is published by LunarWerx, which makes some of the tools compared here.
JAX compiles NumPy programs so they run on TPUs, GPUs and other accelerators [1]. Pythran is an ahead of time compiler for a subset of Python aimed at scientific computing [2]. PyOverdrive, the third option here, patches supported NumPy functions so existing code uses faster paths [3].
| Option | Price | Licence | Install | Notes |
|---|---|---|---|---|
| JAX | Not published | Apache-2.0 [1] | CPU: pip install -U jax [1] | Research project, not an official Google product [1]; supports reverse-mode and forward-mode differentiation [1] |
| Pythran | Not published | BSD-3-Clause [2] | Not published | Python 3.7 and upward only [2] |
| PyOverdrive | Not published | MIT License [3] | pip straight from the GitHub repository [3] | Python 3.12 or newer [3] |
The short answer
JAX compiles NumPy programs so they run on TPUs, GPUs and other hardware accelerators [1]. Pythran is an ahead of time compiler for a subset of the Python language, with a focus on scientific computing [2]. PyOverdrive patches supported NumPy functions so your existing code uses faster paths [3].
JAX's page says it compiles NumPy programs for TPUs, GPUs and other accelerators [1]. Pythran's page says it supports Python 3.7 and upward only [2]. PyOverdrive's sources cover a one-call switch for supported NumPy functions [3], a fallback to stock NumPy for anything outside a measured range [3] and a check that compares every fast path with stock NumPy on your own machine [3].
What JAX and Pythran are built for
JAX. Its page says JAX compiles NumPy programs so they run on TPUs, GPUs and other hardware accelerators [1]. It is licensed under Apache-2.0 [1].
Pythran. Its page calls it an ahead of time compiler for a subset of the Python language, with a focus on scientific computing [2]. The page says it now only supports Python 3.7 and upward [2]. It is BSD-3-Clause licensed [2].
The sources given here say nothing more about either tool, so this page does not describe their speed, limits or typical users.
What PyOverdrive is built for
PyOverdrive is made by the team that publishes this site.
Calling pyoverdrive.enable() patches supported NumPy functions so your existing code uses faster paths, and calls it does not support run on stock NumPy [3]. A fast path runs only when a check confirms the input is in its measured range; anything else, or a fast path that raises an error, goes to stock NumPy [3].
For math functions such as np.sin, cos, tan, exp, log, log10 and tanh on large arrays of decimal numbers, it runs on several processor cores at once above a size that is measured for each operation and data type [3]. For np.linalg.qr on large stacks of 3x3 matrices, it uses a vectorized closed-form method [3]. For large np.einsum calls, it lets NumPy pick a faster plan for the calculation once the input is large enough to benefit [3]. For some text checks with np.isin, it uses a faster lookup method instead of the default one [3].
You can see which path a call would take and why, without running the call, with pyoverdrive.explain() [3].
Pricing and fees
The JAX facts given here state a licence, Apache-2.0, and no price [1]. No fee, paid plan or hosted tier is published in those facts, so none is stated here.
The Pythran facts state a BSD-3-Clause licence [2]. They give no price, fee or paid plan, so none is stated here.
PyOverdrive is open source under the MIT License [3]. Its sources give no price and no paid plan, so a price is not published here. None of the three tools has a fee that sits on top of another company's fee in the facts given.
A licence is not a statement about total cost. Time spent adapting code, and any hardware you choose to run on, are costs these sources do not cover.
Setting it up and daily use
JAX. The CPU install command on its page is pip install -U jax [1]. The page describes compiling NumPy programs for accelerators [1]. The sources here say nothing more about setup for TPUs or GPUs, or about routine use.
Pythran. The sources here give no install command. They say it supports Python 3.7 and upward only [2] and that it is an ahead of time compiler [2]. Check its own documentation for the compile steps.
PyOverdrive. You install it with pip straight from the GitHub repository [3]. It needs Python 3.12 or newer [3]. The package is not tied to one operating system, and its tests have run on Windows and on Linux [3]. The version is 1.0.0 and its status is Beta [3].
You call pyoverdrive.enable() once and keep writing NumPy [3]. A built-in demo compares the timing of the headline operations against stock NumPy on your machine, in about 20 seconds [3]. You can turn off one fast path, or call pyoverdrive.disable() to restore the original NumPy functions [3]. It also turns off any multi-core speed-ups that do not help on your computer [3].
Things to check before you choose
Ask whether your code is written as NumPy. Pythran compiles a subset of Python [2], so check whether your code sits inside that subset. JAX compiles NumPy programs [1], so check whether your code uses NumPy and whether you have suitable hardware.
Check your Python version. Pythran supports Python 3.7 and upward [2], and PyOverdrive needs Python 3.12 or newer [3]. The JAX facts here give no Python version.
Check your hardware. JAX names TPUs, GPUs and other accelerators [1], and the Pythran facts here name no hardware, so check its documentation for what it runs on.
Check the version number and status of each tool. PyOverdrive is version 1.0.0 with Beta status [3].
Check whether the way JAX compiles NumPy programs matches your needs [1], and whether the results must match stock NumPy on your machine, which a PyOverdrive check compares [3].
How to choose
If you want your NumPy programs compiled for TPUs, GPUs or other accelerators, JAX's page says that is its purpose [1].
If you want to compile a subset of Python ahead of time for scientific computing, Pythran's page describes that [2].
If you want to keep existing NumPy code and switch on faster paths with one call, PyOverdrive's claims describe that [3]. If you want unsupported or out-of-range calls to run on stock NumPy, its claims say they do [3].
If you want to turn the faster paths off again, PyOverdrive's claims describe a way to restore the original NumPy functions [3].
Frequently asked questions
Is JAX free and open source?
JAX is licensed under Apache-2.0 [1]. The facts given here do not state a price, a paid plan or a fee, so a price is not published here. Check the project's own pages if you need more detail on costs.
What licence does Pythran use?
Pythran is BSD-3-Clause licensed [2]. The facts given here state no price, fee or paid plan for it, so none is stated on this page. For anything beyond the licence, such as support terms, check Pythran's own pages before you rely on it in a project with commercial or contractual requirements.
How do you install JAX, Pythran and PyOverdrive?
The CPU install command on JAX's page is pip install -U jax [1]. The Pythran facts here give no install command, so check its own documentation. PyOverdrive is installed with pip straight from the GitHub repository [3], and then pyoverdrive.enable() switches the faster paths on [3].
Which Python versions do JAX, Pythran and PyOverdrive need?
Pythran's page says it now only supports Python 3.7 and upward [2]. PyOverdrive needs Python 3.12 or newer [3]. The JAX facts given here do not state a Python version, so check its documentation for the version that matches your release.
How does PyOverdrive decide when to use a faster path?
A fast path runs only when a check confirms the input is in its measured range; anything else, or a fast path that raises an error, goes to stock NumPy [3]. The explain call tells you which path a call would take and why, without running the call [3].
It is open source under the MIT License. [3]
Try PyOverdriveSources
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