Language Categories
Web Frameworks
Modern frontend frameworks with full component support:React
JSX/TSX with React Compiler
Vue
Vue 2 and Vue 3 SFC support
Svelte
Svelte 5 compiler
Solid
Solid.js with JSX
Stencil
Web Components
Riot
Component-based UI
JavaScript Variants
JavaScript
ES2020+ with native support
TypeScript
Full type checking support
CoffeeScript
Ruby-inspired syntax
LiveScript
Functional programming
Civet
TypeScript with CoffeeScript syntax
Imba
Memoized DOM framework
CSS Processors
Powerful CSS preprocessing and utility frameworks:SCSS/Sass
Modern Sass compiler
Less
Dynamic stylesheet language
Stylus
Expressive CSS preprocessor
Tailwind CSS
Utility-first CSS framework
UnoCSS
Instant on-demand atomic CSS
PostCSS
CSS transformation tool
Template Engines
HTML preprocessors and template languages:Pug
Clean, whitespace-sensitive syntax
Haml
HTML abstraction markup
Handlebars
Semantic templates
EJS
Embedded JavaScript templates
Nunjucks
Jinja2-inspired templates
Liquid
Safe, customer-facing templates
Backend Languages
Server-side languages running in the browser:Python
Brython & Pyodide support
Ruby
Opal compiler
PHP
Uniter runtime
Go
Yaegi interpreter
Lua
Fengari & Wasmoon support
Perl
WebPerl runtime
Compiled Languages
Statically-typed languages with WebAssembly compilation:C/C++
Compiled to WebAssembly
C#
WebAssembly support
Go (WASM)
TinyGo WebAssembly
Rust
Via WebAssembly
AssemblyScript
TypeScript-like WASM
WebAssembly
WAT text format
Functional Languages
ReScript
Type-safe JavaScript
Reason
OCaml syntax for React
OCaml
Functional programming
Scheme
Lisp dialect
ClojureScript
Clojure for JavaScript
Common Lisp
JSCL implementation
Data & Query Languages
SQL
SQLite via SQL.js
PostgreSQL
PGlite in-browser
Prolog
Logic programming
MiniZinc
Constraint modeling
Other Languages
- Markdown/MDX: Documentation and content
- AsciiDoc: Technical documentation
- Astro: Multi-framework support
- Diagrams: Mermaid, PlantUML, GraphViz
- Blockly: Visual programming
- Julia, R, Tcl, Teal, Fennel, Gleam: Specialized languages
Language Features
Client-Side Execution
All languages compile and run entirely in the browser:- No server required
- Zero-latency compilation
- Privacy-preserving (code never leaves your browser)
- Offline-capable
Editor Support
Rich editing experience for all languages:- Syntax highlighting (Monaco, CodeMirror, CodeJar)
- IntelliSense and autocomplete
- Error diagnostics
- Format on save
Import Support
Import external packages directly:- npm via esm.sh, jsDelivr, unpkg
- Python packages via Pyodide
- Ruby gems via Opal stdlib
Custom Configuration
Configure compiler options per language:Language Selection
Languages are automatically detected by file extension or can be explicitly set:.js→ JavaScript.ts→ TypeScript.jsx→ JSX.tsx→ TypeScript + JSX.py→ Python.rb→ Ruby.go→ Go- And 80+ more extensions
Performance
Language compilers are loaded on-demand:- Initial page load: ~50KB (core runtime)
- Language compiler: Loaded only when needed
- Cached for subsequent uses
- Progressive Web App support
Browser Compatibility
All languages work in modern browsers:- Chrome/Edge 90+
- Firefox 88+
- Safari 14+
- Mobile browsers supported
Some languages (WebAssembly-based) require browsers with WASM support.
Next Steps
JavaScript
Learn about JavaScript support
TypeScript
Explore TypeScript features
React
Build React applications
Python
Run Python in the browser