Language playgrounds and small coding utilities — no install, no account.
Write JavaScript, run it in a sandbox, and inspect console output.
Transpile TypeScript in the browser and run the emitted JavaScript.
Run Python with Pyodide — live console, snippets, and local autosave.
Edit HTML, CSS, and JavaScript together with a live preview.
SQLite in your browser — sample data, queries, and result tables.
Run Lua via Fengari with print wired to a live console.
Pretty-print, minify, and validate JSON with adjustable indent.
Match patterns against sample text with live highlights and groups.
Base64, URL, and HTML entity encode or decode in place.
SHA-1 / 256 / 512 digests and random UUID v4 via Web Crypto.
Compare two texts line by line and spot additions and removals.
Inspect header and payload claims. Decode only — no signature check.
Write Markdown and preview HTML side by side. Autosaves locally.
Paste a cron expression — plain English plus upcoming run times.
Generate UUID v4 and ULID identifiers one at a time or in bulk.
Create a downloadable QR code from any URL or text.
Convert and validate YAML and JSON in either direction.
Encode files to Base64 or decode Base64 back to a download.
Pretty-print GraphQL queries and JSON variables.
Strip comments and compress CSS or JavaScript snippets.
Send HTTP requests from the browser and inspect the response.
Paste once, detect the shape, then jump into JSON, regex, hash, encode, and more.