JavaScript formatter

Format code and locate syntax errors.

On your device · No account

Privacy details

JavaScript formatter processes your input in this browser. Inputs and results are excluded from analytics. Recent tools save tool names, visit counts and last-visit times. Saved tools store only their names. Draft saving is optional and stays on this device; delete saved text with the draft controls. Loading text from a URL is optional and contacts that server; its URL and your IP address are visible to the server. An optional “Use in” action keeps a handoff in this tab. The next tool removes it on arrival and ignores it if more than a minute has passed.

Copy link includes the inputs you choose to share in the address. Anyone with that link can reopen them. Files and generated results are excluded. Password and key tools share settings only.

Your code

Options and local file

Indentation

Open a text file on this device

Optional settings apply only to this tab.

Your result

Save a draft on this device

Save edits to this draft

Saving is off. Anyone using this browser profile can read a saved draft. Nothing is uploaded.

Reset reloads the tool with its starting values and releases open files and device controls. Saved drafts stay on this device until you delete them.

Links include your inputs and settings. Anyone with the link can see them, so leave out private text. Files and generated results are left out; random draws run again.

Keyboard shortcuts

Updated 2026-09-26

JavaScript formatter explained

Paste JavaScript to format it with the bundled Prettier 3.9.8 parser. The output is parsed again and checked for stable formatting before Copy or Download becomes available.

Next: TypeScript formatter

Next: CSS formatter

A worked example

For example, const n=1 becomes a consistently spaced JavaScript document. Incomplete brackets or quotes show a syntax error and leave your input available to correct.

Before you use the result

JavaScript and JSX are parsed without executing them. Syntax validity does not establish runtime correctness, safety or type correctness. This formatter does not minify; removing whitespace without a language-aware minifier can change meaning.

Cite this page

Citation style

ToolOctopus. “JavaScript formatter.” Updated 2026-09-26. https://tooloctopus.com/javascript-formatter.

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