Online Compilers & Code Playgrounds
Code runs on your device in workers and sandboxes, so nothing is uploaded and infinite loops can always be stopped.
- Python Online CompilerRun Python in your browser with input(), instant output and a NumPy-style array module.
- JavaScript PlaygroundRun JavaScript with a real console, async/await, timers and console.table.
- TypeScript PlaygroundType-check TypeScript with the real compiler, see errors by line and run the result.
- SQL PlaygroundPractise SQL on SQLite with sample databases, joins, CTEs and window functions.
- HTML, CSS & JS EditorEdit HTML, CSS and JavaScript with a live preview and console in a safe sandbox.
- Mermaid EditorWrite Mermaid diagrams as text and see flowcharts, sequences, Gantt and ER diagrams live.
About Online Compilers & Code Playgrounds
Code playgrounds that run entirely in your browser. Python runs on MicroPython compiled to WebAssembly, JavaScript and TypeScript run in disposable Web Workers with a developer-style console, SQL runs on SQLite with sample databases, and the HTML, CSS & JS editor previews your page in an isolated sandbox.
Every runner has a time limit and a Stop button, drafts are kept in this browser, and share links carry the code in the URL fragment, which is never sent to a server. The Mermaid editor turns diagram text into SVG and PNG files.