Run JavaScript, TypeScript, Python, SQL, Lua and HTML in your browser

Write a snippet and run it without uploading it or configuring a runtime. Code runs in a sandboxed worker on your machine, so a script that builds a data structure or tests a regex finishes before a network round trip would have started.

Compiler — Run JavaScript, TypeScript, Python, SQL and Lua in a sandbox, and preview HTML. (Web Worker · no upload)

What it does

• Six languages, one tab — JavaScript, TypeScript, Python, SQL (SQLite) and Lua run in sandboxed workers, and HTML/CSS renders in a sandboxed preview frame, with the output pane and the editor in one window. The Python, SQL and Lua runtimes are downloaded from jsDelivr the first time you use them.
• Runs on your device — Your source is executed in a sandbox on your own device, not on a hosted runner. It leaves the tab only if you use an AI action (such as Explain this error), which sends the code it names to the AI provider you chose.
• Timeouts on every run — Execution is bounded by a strict timeout, so an accidental infinite loop stops rather than freezing the page.

What it does not do

This runs snippets, not projects: there is no npm install, no multi-file build step and no package registry behind it.

InTab is free and runs in this browser tab. There is no account, no sign-up and no login screen. Requests leave the tab when you start them — an AI prompt to the provider you chose (including the AI actions in each tool, which send the content they name), an API call, a web search, or an optional encrypted backup to your own Google Drive or OneDrive. Read the privacy policy for what each of those sends, and where.

Other tools in InTab

• Agents — Stream AI answers from top models with your own API key.
• Formatters — Prettify and validate JSON and XML with inline error locations.
• Converter — Convert images, documents, spreadsheets, data and archives without uploading them.
• Diff Check — Compare files side-by-side or inline with whitespace controls.
• Comparators — Audit .env files, JSON, and text lists for missing, extra and changed keys.
• API Tester — Send REST, GraphQL, and WebSocket requests directly from your tab.
• Library — Search 148 bundled ServiceNow APIs and their 1046 documented methods.
• DrawFlows — Diagram architectures on an infinite canvas with 230+ shape packs.