Keyboard shortcut
Press Ctrl + Enter or ⌘ + Enter to run. Tab remains normal keyboard navigation.
Browser playground
Edit, run, inspect, repeat.
Run a real ES module against the deployed package source. vanilla-test works with bundlers and without a bundler. Every run starts in a fresh opaque-origin sandbox that cannot read this page's origin, storage, or cookies.
Check the console or DevTools.
Console output is mirrored into the panel below, including recognized ansi-colors-es6 styling, and remains available in your browser's developer tools.
Native no-bundler demo plumbing.
The sandbox creates an explicit blob-URL import map for vanilla-test, ansi-colors-es6, and strong-type before importing your module. A deployed npm app instead uses the complete document-relative map in the browser guide, serves it over HTTP(S), and exposes its mapped files; file:// is not supported. Neither path needs a build or transpilation step.
ES module
Console
Fresh sandboxPreparing the isolated runtime…
Loading package source…
What the sandbox does
It runs one module with the vanilla-test package specifier available. A restrictive sandbox policy blocks ordinary network requests, a 15-second watchdog resets stalled runs, and mirrored output is bounded.
Need a production-ready pattern? Start from a complete adapter, then use the API contracts to handle results and events.