Online Compiler and Code Runner
Write and run Python, JavaScript, TypeScript, React/JSX, SQL, HTML, CSS, JSON, Markdown, YAML, XML, CSV, and SCSS in a professional browser coding workspace. No desktop setup, no fake server-language claims, and no signup.
function greet(name: string): string {
return `Hello, ${name}!`;
}
console.log(greet("ToolerWork"));Built only for languages that can run or preview well in the browser
Choose the right online runner for your code
Each language page explains exactly how code is processed, which files work, and where the browser-first runner stops. Open the focused page before launching its editor.
| Language | Browser runtime | Files | Best use |
|---|---|---|---|
| Python | Python 3 through Pyodide WebAssembly | .py | Practice Python basics |
| JavaScript | Modern JavaScript in a browser Web Worker | .js, .mjs, .cjs | Test JS snippets |
| TypeScript | TypeScript transpilation followed by JavaScript Worker execution | .ts | Try TypeScript functions |
| HTML/CSS/JS | Sandboxed browser iframe preview | .html, .css, .js | Preview landing snippets |
| CSS | CSS rendered in a sandboxed HTML preview | .css, .html, .js | Test Flexbox and Grid |
| JSON | Native browser JSON parser and formatter | .json | Validate JSON payloads |
| Markdown | Safe client-side Markdown preview | .md, .markdown | Draft README files |
| SQL | SQLite through sql.js WebAssembly | .sql | Practice SQL basics |
| React/JSX | React and Babel inside a sandboxed browser preview | .jsx | Practice React components |
| YAML | Lightweight local YAML parser | .yaml, .yml | Check config snippets |
| XML | Native browser DOMParser and XMLSerializer | .xml | Validate XML snippets |
| CSV | Local character-by-character CSV parser | .csv | Check CSV rows |
| SCSS | ToolerWork lightweight SCSS subset compiler | .scss, .sass | Practice SCSS variables |
A real local browser workspace
- Monaco editor with syntax highlighting and snippets
- Local project files with autosave
- Worker-based JavaScript and Python execution
- Client-side SQLite SQL runner
- React/JSX sandbox preview
- TypeScript transpilation before run
- Sandboxed HTML/CSS/JS and SCSS preview
- Output, console, problems, input, and preview panels
Open, edit, run, save
- Open the Code Studio workspace.
- Choose a language or starter project.
- Edit files in the Monaco code editor.
- Run code, check output, and save locally.
MVP code runs locally
Code Studio uses browser workers, local project storage, WebAssembly where useful, and sandboxed preview frames for supported browser-first languages. Heavy server languages still belong in a future backend phase instead of fake client-side support.
Code Studio questions
Can I run Python online?
Yes. Python runs through Pyodide inside a browser worker and loads only when needed.
Can I run TypeScript?
Yes. TypeScript is transpiled in the browser and then executed as JavaScript in a worker.
Can HTML projects use separate files?
Yes. Web starters use index.html, style.css, and script.js in a virtual local project.
Will Java or C++ be added?
They are planned for a future Judge0-style backend phase, not as fake MVP support.