Built for speed and simplicity
Everything you need to experiment, prototype, and execute code across multiple languages.
Lightning Fast
Built with Rust for maximum performance. Execute code snippets in milliseconds.
25 Languages
Python, JavaScript, TypeScript, Rust, Go, C, C++, Java, Kotlin, C#, Swift, Ruby, PHP, Lua, Bash, Dart, R, Perl, Haskell, Elixir, Julia, Crystal, Zig, and Nim.
Stateful REPL
Stateful REPL with language switching. State persists across commands in all supported languages.
Inline Execution
Run code snippets directly from the command line without creating files.
Auto-Detection
Automatically detects language from file extensions and code patterns.
File & Stdin Support
Execute files, pipe stdin, or run inline snippets with the same command.
All your favorite languages
Switch between 25 languages instantly with simple commands. No configuration needed.
Try It Live
Interactive demo - type commands and see them execute
Try: run python --code "print(2+2)" or :languages
See it in action
Multiple ways to run code. Choose what works best for your workflow.
Built for Developers
From quick experiments to production scripts, run adapts to your workflow
Quick Prototyping
Test ideas instantly without setting up project environments. Switch between languages in seconds.
run python --code "import requests; print(requests.get('api.com').json())"Learning New Languages
Experiment with syntax and features across 15+ languages without installing separate tools.
run rust
rust>>> println!("Hello from Rust!");
rust>>> :lang go
go>>> fmt.Println("Now in Go!")Testing Code Snippets
Validate algorithms, test functions, and debug logic interactively with stateful execution.
python>>> x = [1, 2, 3] python>>> sum(x) 6
Scripting & Automation
Execute scripts in any language from the command line. Perfect for CI/CD pipelines and automation.
run script.py run deploy.js run build.sh
Code Golf & Challenges
Solve coding challenges and compare solutions across different languages instantly.
run js --code "console.log([...Array(10)].map((_,i)=>i*i))" run python --code "print([i**2 for i in range(10)])"
Live Demos & Teaching
Demonstrate code execution in real-time. Switch languages on the fly during presentations.
:lang python python>>> # Show Python :lang js javascript>>> // Now JavaScript
Command Reference
Quick reference for all commands and usage patterns
REPL Commands
:helpShow all available REPL commands and their usage
:languagesList all 15+ supported programming languages
:lang <id>Switch to a different language REPL (e.g., :lang rust, :py, :js)
:detect on|offToggle automatic language detection from file extensions
:resetReset the current language session and clear state
:load <path>Execute a file in the current language context
:exit / :quitExit the REPL and return to your shell
CLI Usage
runStart interactive REPL with auto-detection
run <language>Start REPL for specific language (e.g., run python, run js)
run <file>Execute a file (language auto-detected from extension)
run <lang> --code "..."Execute inline code snippet
cat file.py | runExecute code from stdin
Quick Aliases
Get started in seconds
Install run with a single command. Requires Rust 1.70 or newer.
Clone the repo
Clone from GitHub and navigate to the project directory.
Build with Cargo
Run the install command to build the binary with your Rust toolchain.
Start coding
Use run to execute code in any supported language.
Frequently Asked Questions
Everything you need to know about run