Keyboard Repeat Pattern Explorer

A lightweight web app for observing how your system generates repeated keydown events when multiple keys are held simultaneously. Use it to compare repeat behavior across keyboards, browsers, and operating systems.

Live demo

Once this repository is published to GitHub Pages the site will be available at:

https://<your-github-username>.github.io/KeyboardTesterWasm/

(Replace <your-github-username> with the account or organization that owns the repository.)

Local development

The interface lives in the docs/ folder so it can be published with GitHub Pages using the “Deploy from a branch” option targeting the main branch and /docs directory. All interaction logic now runs inside a Rust WebAssembly module that is embedded into the page as base64 text so no binary artifacts need to be committed.

Build the WebAssembly bundle

Install wasm-pack if you do not already have it:

cargo install wasm-pack

Compile the Rust crate under wasm/ to WebAssembly outputs inside docs/pkg:

wasm-pack build wasm --target web --out-dir docs/pkg --release

Then convert the generated .wasm file into the embedded base64 module and remove the binary artifact:

./scripts/embed-wasm.sh

Note: wasm-pack is configured to skip wasm-opt so the build works in minimal environments. If you have Binaryen installed you can remove that override from wasm/Cargo.toml to enable additional optimizations.

Preview the site locally

Serve the repository root with any static file server and open http://localhost:8000/docs in a browser:

python3 -m http.server 8000

How it works

• Held keys panel – shows which keys are currently pressed.
• Repeat pattern – displays the order of recent repeated keydown events plus a running tally per key.
• Event timeline – logs every keydown and keyup event with timestamps and inter-event deltas to help you detect rotation patterns or biases.

Use the Pause capture toggle to temporarily stop logging without resetting existing data, or Clear log to reset the session.