What is Handwired.wiki?
Handwired.wiki is an interactive learning tool and demo gallery for Handwired, the project by Cheng Lou that turns regular JavaScript into a neural net. No training needed, exact, and still fully differentiable.
You write ordinary JavaScript builder code once. Handwired turns it into a small network of arithmetic and ReLUs that gives the same answers as your code. Then you can let data tune its numbers while your rules stay exactly as written. The site shows that happening live, in the browser, using the real Handwired runtime.
Why We Built It
Handwired is easy to describe and hard to picture. "Your code, as a neural net" sounds like a trick until you watch it work.
The interesting part is what it lets you do: keep the rules you trust, and let data adjust the constants you were guessing at. A hand-tuned search formula can learn its weights from shopper clicks and still always put the pinned result first. A generic model trained on the same clicks has no reason to keep that rule.
We built Handwired.wiki so people can see that difference for themselves instead of taking it on faith.
A Hands-On Way to Watch Code Learn
The home page opens on a live demo. You let 1,000 simulated shoppers into a store search and watch two models learn side by side: your formula as a Handwired net, where learning moves four numbers you can read, and a generic net, where it moves 65 that nobody can. Then you check which one still keeps pinned items first and out-of-stock items out of the top ten.
For a gentler start, there is a three-minute beginner lesson about a cat deciding how hard to jump, comparing plain JavaScript with a neural net.
Built Around Real Use Cases
Each demo is a job you might actually have:
- Ranking from clicks, where "pinned first" and "never show out-of-stock" stay exact.
- Layout from a designer's examples: drag a few cards to the sizes you want and every card follows, with zero overflows.
- Physics from a recording: fit gravity, drag and bounce so a simulated ball matches a recorded path.
- Accessible colour themes: point at colours you like, and every text pair still passes WCAG AA in light and dark.
- Searching 100,000 JSON documents on the GPU, based on Cheng Lou's own demo.
Alongside the demos are pages on why Handwired matters, the core concepts, getting started, and an FAQ drawn from Cheng Lou's README and docs.
Useful for Developers Who Have Rules and Data
Handwired.wiki is for people who already have readable code with a few constants, some rules that must never break, and data that should tune the rest. That covers search and ranking, layout systems, simulations, design tooling, and accessibility work.
If you have no trusted code and lots of data, a regular model is probably the better tool, and the site says so.
Built to Make the Idea Click
Some ideas land from a README. This one lands when you watch a model learn and still keep every rule.
Handwired.wiki exists so more people can see what Handwired does, when it fits, and how to start writing builder code of their own.
Handwired is Cheng Lou's work, released under the MIT license; his repo and docs are the authoritative reference. Handwired.wiki is not official and not affiliated with or endorsed by him.