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JSON Preview

Format, validate and explore any JSON you paste

About this tool

JSON that comes back from an API or shows up in a log file is usually a single unreadable line. Paste it here and you get the formatted document and a structural tree at the same time, which makes finding the key you actually care about much faster.

If the document does not parse, the error is reported with the line and column where parsing failed. Missing commas and the wrong kind of quote mark are quick to spot once you know where to look.

Beyond formatting, you can switch the indent width, sort object keys alphabetically and strip every unnecessary space. Sorting keys makes the diff between two config files meaningful; minifying cuts the size of a payload you are about to send.


How to use it

  1. Paste JSON into the left pane — a single unformatted line is fine.
  2. The formatted result appears on the right. Switch tabs to explore it as a tree.
  3. Use the toolbar to change indentation, sort keys or minify the output.
  4. Press copy to put the formatted text on your clipboard.

Features

Errors with line and column

Syntax errors are reported with the exact position, so you can go straight to the problem.

Collapsible tree

Explore deeply nested responses by expanding only the branches you need.

Formatting options

Two spaces, four spaces or tabs, with optional key sorting and minification.

Nothing leaves the page

Parsing happens locally, so responses containing tokens or personal data stay on your machine.


Frequently asked questions

How large a document can it handle?

A few megabytes is fine. Because everything runs in the browser, very large files may make rendering sluggish.

Does it accept trailing commas or comments?

No — parsing follows the JSON specification, so both are reported as errors. The error position tells you what to remove.

Does sorting keys change my data?

No. Sorting only reorders the keys of each object; values and structure are untouched.

Can I save the formatted output?

Copy it to your clipboard and paste it into an editor. Your input itself is saved in the browser automatically.