A JSON toolkit that stays in your browser.

Why it exists

Most online JSON tools POST your document to a backend just to add some indentation. That is an odd trade: you hand a config file, an API response, or a production payload to a stranger's server in exchange for whitespace. Plenty of those documents contain tokens, customer records, or internal identifiers that were never meant to leave your machine.

None of that is necessary. Everything a JSON tool has to do — parse, re-serialize, walk a tree, diff two structures, read a local file — the browser already does natively. So this site does it there, and the server only ever sends you a static page.

What it does

• JSON formatter — Indent JSON with 2 spaces, 4 spaces, or tabs, then copy or download the result.
• JSON viewer — Expand, collapse, and search a JSON tree; copy any value or its path.
• JSON validator — Find syntax errors with exact line, column, and a suggested fix.
• JSON minifier — Strip whitespace and see the byte savings before and after.
• JSON beautifier — Turn minified or broken JSON into clean, highlighted output.
• JSON pretty print — Readable indentation with optional deep key sorting.
• Converters — JSON to and from CSV, YAML, and XML.
• Diff — compare two documents by path, ignoring key order and indentation.

How it is built

A static site with no backend. Parsing uses the browser's own JSON.parse, file opening uses the local File API, and fonts are compiled in at build time so the page makes no third-party requests. There is no analytics, no advertising, and no tracking of any kind — see the privacy policy for the details.

What it costs

Nothing, and there is no account to create. The site is free to use for personal and commercial work alike, under the terms and conditions.

Feedback

Bug reports, a payload that breaks a parser, or a tool you wish existed:support@jsonformatterviewer.com, or thecontact page.