JavaScript Editor: React JS TS

CosmoVex

Contains adsIn-app purchases

About this app

Write JavaScript, TypeScript and React on your Android phone. A real code editor with a live preview, npm packages, multi-file projects, and one tap to put your work on the web.

JavaScript Editor is a mobile development environment for web developers, students and interview preppers. The editor, the console and the React preview all run on your device.

WHAT YOU CAN DO

• Write JavaScript and run it with console output — logs, warnings and errors, inline
• Write React components with JSX and watch a live preview render on your device
• Write TypeScript and TSX with types stripped automatically before your code runs
• Split a project across multiple files and folders, and import between them
• Pull in npm packages with a normal import statement
• Publish a project to a link you can open in any browser and send to anyone
• Open and save .js, .jsx, .ts and .tsx files anywhere on your device

MULTI-FILE PROJECTS

Real apps are not one file. Add components and folders, import between them with ordinary relative paths, and switch files from a tab strip built for a phone screen. Your entry file mounts automatically when you tap Run.

TYPESCRIPT

Turn on TypeScript and write .ts and .tsx with interfaces, generics and typed props. Types are stripped before execution, so your code runs the moment you tap Run.

NPM PACKAGES

Import a package by name and it resolves when you run. No terminal, no install step, no config file. Bring in a UI library, a date helper or an animation package and use it straight away.

PUBLISH TO THE WEB

Turn any project into a link. Multi-file imports, npm packages and TypeScript are all included, exactly as they run in the app. Change your code and publish again — the link stays the same and shows the new version. Take a page down whenever you want.

CODE EDITOR

Syntax highlighting, word wrap, a symbols bar for punctuation you would otherwise hunt for, a React hooks shortcut bar, find and replace, and undo history with real depth. Monospace typography for small screens, adjustable font size and indent width, and a set of dark editor themes.

JAVASCRIPT CONSOLE AND DEBUGGING

Run any snippet and read the console below the editor. Colour-coded levels for log, info, warn and error, timestamps, and one-tap clear. Errors surface where they happened, so you can find the line that broke and fix it.

REACT PREVIEW

Tap Run and your component mounts to a live preview pane below the editor. Edit CSS with one tap. Go fullscreen to inspect the result on the whole screen.

EXAMPLES GALLERY

Curated JavaScript and React examples — arrays and iteration, async and await, closures, classes, fetch, hooks, state, dynamic lists, forms and visual effects. Filter by JavaScript or React with a tab.

SAVE, OPEN AND EXPORT

Save to the app or to your device through the system dialog. Open existing files straight from your phone; the extension picks the right mode. Export a project as a standalone HTML file that runs in any browser.

WHO IT IS FOR

• Web developers sketching a component away from their laptop
• Students learning JavaScript, TypeScript, React or the DOM
• Interview preppers practising algorithms in real JavaScript
• Self-taught coders following tutorials on a phone
• Anyone who wants a mobile JavaScript playground that saves real work

A PRO UPGRADE IS AVAILABLE

The editor, the console, the React preview and the examples gallery are free to use. A Pro upgrade removes ads and opens up multi-file projects, TypeScript, publishing, editor themes, custom snippets, find and replace, and one-tap formatting.

LANGUAGES

Available in 16 languages including English, Spanish, Portuguese, French, German, Russian, Hindi, Bengali, Indonesian, Turkish, Urdu, Arabic, Somali, Chinese (Simplified), Japanese and Korean.

What’s new

Fixed: no ad-consent screen in front of a new install. The app opens straight into the editor, and if your region requires a consent choice it is asked later — never before you have used the app. You can change or withdraw that choice any time in Settings > Ad Privacy Choices.