# Numba

30 Hacker News commenters recommended Numba and 9 criticized it, November 2025 to November 2026. It was recommended in 9 of 13 months. It meets the Hacker Approved badge rule.

**Verdict:** Speeds up numerical Python code by compiling decorated functions, especially numpy and parallel loops. Caveat: only partly compatible with CPython and best on code of a particular shape.

## Why people recommend it

- Easy speedups with a decorator (4 comments): "there's some low hanging fruit with numba. I would recommend this as a 5-minute solution" ([source](https://news.ycombinator.com/item?id=48646820)) "you add a decorator to your function and it turns it into compiled code" ([source](https://news.ycombinator.com/item?id=49264508)) "tools like numba can beat them all at way less effort." ([source](https://news.ycombinator.com/item?id=48069219))
- Great for numpy number crunching (3 comments): "Numba is great at optimizing numpy code but not necessarily other general Python code." ([source](https://news.ycombinator.com/item?id=50264139)) "It's great for number crunching." ([source](https://news.ycombinator.com/item?id=46560724)) "please do at least use Numba or Numpy so you aren't paying huge overheads for making an object of every little datum" ([source](https://news.ycombinator.com/item?id=46455578))
- Speed close to C or Cython (2 comments): "Generally as fast as Cython, but much easier to write." ([source](https://news.ycombinator.com/item?id=50265894)) "it will be roughly as fast as similar C code" ([source](https://news.ycombinator.com/item?id=46457492))

## What people warn about

- Heavy install, system requirements (2 comments): "it was a pain due to extensive system requirements or alternatively requiring use of conda" ([source](https://news.ycombinator.com/item?id=50267528)) "Numba+llvmlite alone is almost 100MB!" ([source](https://news.ycombinator.com/item?id=49317231))
- Only partly compatible with CPython (2 comments): "use Numba JIT'd Python that is only partially compatible with CPython" ([source](https://news.ycombinator.com/item?id=49411143)) "appears like Python but are nothing like Python as soon as you scratch the surface" ([source](https://news.ycombinator.com/item?id=48063595))
- Needs code in a specific shape (2 comments): "It's JIT only, and it needs to be in a particular shape to be effectively compiled." ([source](https://news.ycombinator.com/item?id=49266853)) "Numba is great at optimizing numpy code but not necessarily other general Python code." ([source](https://news.ycombinator.com/item?id=50264139))

## Alternatives hackers recommend

- [CPython experimental JIT](https://hackerapproved.com/p/cpython-experimental-jit.md): 13 recommend
- [YJIT](https://hackerapproved.com/p/yjit.md): 10 recommend
- [HotSpot JVM](https://hackerapproved.com/p/hotspot.md): 8 recommend
- [ZJIT](https://hackerapproved.com/p/zjit.md): 7 recommend
- [Mir JIT compiler library](https://hackerapproved.com/p/mir.md): 6 recommend

## Cite as

Hacker Approved, "Numba", https://hackerapproved.com/p/numba/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).