JSON Formatter

Expand a one-line API response so you can read it, or minify it back for transport. Format, minify, validate, and sort keys all run locally.

When you debug an API, the backend often returns minified JSON. Nesting is hard to see and array items are easy to miss. Paste on the left, click Format, and the right pane indents it.

Indent can be 2 spaces, 4 spaces, or Tab. When you need to compare key order, Sort keys first, then copy. Syntax errors show in the status bar — no extra validator.

Data is handled in this browser only. Good for responses that contain tokens, user profiles, or internal fields.

When to use Format

You copied a response from the Network panel, pulled JSON from a log, or a coworker sent minified text. Format is for readability. It does not change business meaning.

What Minify and Sort keys do

Minify strips extra whitespace so you can drop JSON into a URL, env var, or size-sensitive body. Sort keys reorders object keys alphabetically so a text Diff is easier — don't treat that order as a stable API contract.

How to use it

Paste JSON on the left, or click Load sample to see a structure.
Pick indent: 2 spaces, 4 spaces, or Tab — match your repo.
Click Format to expand, Minify for one line, or Validate if you only need to know it parses.
If two objects have messy key order, Sort keys before you copy.
Copy result takes the output. Ctrl / ⌘ + Enter formats too.

When to use it

Copy a minified response from Chrome DevTools and expand the field tree.
Crush multiline JSON into one line for a .env or a CLI argument.
Validate before you commit so trailing commas or comments don't hit an API that only accepts standard JSON.
Sort keys, then text-diff the config against another environment.

Keep in mind

Invalid JSON is not overwritten: the original stays on the left, the error in the status bar.
Numbers, strings, booleans, and null stay as-is. Format does not change business values.
Huge files depend on browser memory. A few MB is usually fine; larger files belong on jq or another CLI.

FAQ

How large a JSON can I format?

A few MB usually feels smooth, depending on browser memory. Huge files belong on a CLI.

Does Format change field values?

No. It only adjusts whitespace and optional key sorting. Numbers, strings, and booleans stay the same.

What happens with invalid JSON?

If validate or format fails, the status bar shows the error location. The original is not overwritten.

Is my data uploaded?

No. Everything stays local. Refreshing the page does not sync your input to the web.

What about comments and trailing commas?

Standard JSON allows neither. Clean or Repair first, then come back to Format.

Can I restore minified JSON?

Yes. Minify only removes whitespace. Format expands it again with your indent.

Does sorting keys affect arrays?

Array order stays put. Only object keys are reordered.

When should I use Tree view instead?

Use this page to edit text and copy a pretty result. Use Tree view to scan hierarchy.