# QuickJS

33 Hacker News commenters recommended QuickJS and 8 criticized it, November 2025 to November 2026. It was recommended in 10 of 13 months. It meets the Hacker Approved badge rule.

**Verdict:** Small, self-contained, fast C JavaScript engine by Fabrice Bellard that matches almost all of ES2025 and is easy to embed. Critics say it is much slower than JIT engines such as V8.

## Why people recommend it

- Small and lightweight, low resource use (5 comments): "Hermes and QuickJS both come out looking very good in these (in terms of performance vs. binary size)" ([source](https://news.ycombinator.com/item?id=45945511)) "use a lightweight runtime (QuickJS or even the new Micro QuickJS)" ([source](https://news.ycombinator.com/item?id=46413435)) "QuickJS and LLRT which use like 1000x less resources than v8" ([source](https://news.ycombinator.com/item?id=49931707))
- Simple, portable pure C code (4 comments): "I was amazed to discover he created the entirety of JavaScript in a single xxx thousand line C file" ([source](https://news.ycombinator.com/item?id=46368570)) "it only takes a few seconds at worst. That's great news for portability!" ([source](https://news.ycombinator.com/item?id=45908906)) "which is written in pure C and should work on anything" ([source](https://news.ycombinator.com/item?id=45901292))
- Embeddable and self-contained (3 comments): "It's pretty handy for things like untrusted user authored JS scripts that run on a user's client." ([source](https://news.ycombinator.com/item?id=46371885)) "embeddable, self contained (no libs) and fast JavaScript engine matching almost entirely ES2025" ([source](https://news.ycombinator.com/item?id=48553180)) "I easily managed to build quickJS to WebAssembly for running in exaequOS.com" ([source](https://news.ycombinator.com/item?id=46367372))
- Performance adequate for embedding (3 comments): "Hermes and QuickJS both come out looking very good in these (in terms of performance vs. binary size)" ([source](https://news.ycombinator.com/item?id=45945511)) "performed more than adequately for the kind of thing this class of software needs" ([source](https://news.ycombinator.com/item?id=49928308)) "A 5x slowdown for an interpreted C JS engine is pretty good I think" ([source](https://news.ycombinator.com/item?id=45904858))

## What people warn about

- Much slower than JIT engines (5 comments): "Quickjs (despite being pretty good) can't match the performance of sophisticated JIT implementations like V8 or JavaScriptCore" ([source](https://news.ycombinator.com/item?id=46371019)) "quickjs/mquickjs are good at embedding but nowhere close to luajit in terms of speed" ([source](https://news.ycombinator.com/item?id=47016678)) "QuickJS also pays a performance tax (no JIT) and still doesn't give you the OS" ([source](https://news.ycombinator.com/item?id=48446036))
- Weak as a security sandbox (2 comments): "how extremely weak a C executable like QuickJS is for LLMs to exploit" ([source](https://news.ycombinator.com/item?id=46686191)) "not trusting that as a sandbox to the same degree" ([source](https://news.ycombinator.com/item?id=46370003))
- Slow on old hardware or wasm (2 comments): "Even Edbrowse can grind down to a halt an n270 netbook because of some sites with JS (both with qjs and qjs-ng)." ([source](https://news.ycombinator.com/item?id=46373830)) "You lose a non-trivial amount of performance running js inside quickjs inside of wasm" ([source](https://news.ycombinator.com/item?id=46368972))

## Alternatives hackers recommend

- [V8 JavaScript engine](https://hackerapproved.com/p/v8.md): 59 recommend
- [MicroQuickJS](https://hackerapproved.com/p/microquickjs.md): 19 recommend
- [JavaScriptCore](https://hackerapproved.com/p/javascriptcore.md): 14 recommend
- [Boa JavaScript engine](https://hackerapproved.com/p/boa-javascript-engine.md): 14 recommend
- [SpiderMonkey](https://hackerapproved.com/p/spidermonkey.md): 8 recommend

## Cite as

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