$ ls -lh ./tools
// client-side only. nothing you type here ever leaves your browser.
JWT Decoder
Decode a JWT's header and payload. No signature verification, no network calls.
run ./jwt-decoder →Cron Parser
Human-readable explanation of a cron expression, plus its next run times.
run ./cron-parser →Unix Timestamp Converter
Convert between Unix epoch and human-readable dates, local and UTC.
run ./timestamp-converter →Python REPL
Real CPython compiled to WebAssembly (Pyodide). Runs entirely in your browser.
run ./python-repl →Lua REPL
A real Lua VM (Fengari) compiled to JavaScript. Runs entirely in your browser.
run ./lua-repl →DOS Emulator
js-dos in your browser. No games hosted here — upload your own bundle, or boot a bare prompt.
run ./dos-emulator →Retro Console Emulator
NES, SNES, Genesis, Game Boy, Atari 2600, Amiga, C64, ZX Spectrum — via EmulatorJS. Upload your own legally-owned ROM, nothing is hosted here.
run ./retro-emulator →Linux in Your Browser
A real x86 PC emulated via WebAssembly (v86), booting an official Alpine Linux ISO. Runs entirely client-side.
run ./linux-vm →