Your work crosses languages — a Python function today, a Go benchmark tomorrow. You want SQL, an HTTP client, and 31 utilities in the same window as your code. You want AI that never sends your code to a cloud you did not choose.

You only ever write JavaScript or TypeScript and want the most focused tool for exactly that. You rely on a specific RunJS workflow detail you already know by heart.

Honest comparison

Lingua vs RunJS

RunJS pioneered the instant-feedback JS scratchpad and it is still one of the best at exactly that. Lingua is a broader local-first lab: the same scratchpad feel, plus four more languages, SQL and HTTP workspaces, a utility shelf, and AI that runs on a local model. If you only touch JavaScript, RunJS is a fine, focused pick. If your day crosses languages, keep reading.

CapabilityLinguaRunJS

JavaScript & TypeScript scratchpadthe original strength

Node runtime with require() of npmdesktop, from your project node_modules

Python, Go, Rust, Ruby runners

SQL workspace (DuckDB) & HTTP client

Built-in developer utilities31 panels

AI assistanceruns on a local model, BYO-keycloud AI chat

Runs in a browser, no install

Notebooks with a shared kernel

Choose Lingua when

Your work crosses languages — a Python function today, a Go benchmark tomorrow.
You want SQL, an HTTP client, and 31 utilities in the same window as your code.
You want AI that never sends your code to a cloud you did not choose.

Choose RunJS when

You only ever write JavaScript or TypeScript and want the most focused tool for exactly that.
You rely on a specific RunJS workflow detail you already know by heart.

Try Lingua in your browserNo install, no account.