No. Formatting, conversion and preview work happens in your browser.

What should I check before publishing?

Review syntax errors, warnings, rendered previews and minified output before pasting changes into production code.

JavaScript Formatter Online

JavaScript Formatter

Format JavaScript snippets locally with Prettier.

Input

JavaScript

Output

JavaScriptread only

Input size

86 B

Output size

Saved

JavaScript Formatter is built for snippets, docs, demos and quick reviews where consistent formatting matters but opening an IDE is too slow.

The work runs locally in your browser. Use the sample, review errors or warnings, then copy or download the result without signing in.

javascript formatterjavascript formatter onlinedeveloper formatter

No. It only parses and formats code locally; it does not run the script.

Apply lightweight TypeScript spacing for readable snippets and examples.

Format HTML tags into readable nested markup for snippets and templates.

Format, validate, minify and debug JSON from APIs, configs, webhooks and logs

Run JavaScript snippets safely in the browser for learning, practice and quick debugging