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.