DEVELOPER TOOLS

JSON Formatter & Validator

Make an API response readable, repair a syntax error, or inspect a value’s path. Your input stays in this browser.

Open .json file Format as I type

JSON input · drag a file here

Formatted output

Indentation

Up to 2 MB. Ctrl/Cmd + Enter to format. Syntax validation does not check an API schema. Unsafe integers are flagged before formatting; duplicate keys and decimal representation can still change on parsing.

Inspect JSON paths & values

Filter paths or values

Why JSON formatting matters

JSON is compact by design, but compact text is hard to review when you are debugging API responses, webhooks, configuration files, or test payloads. Formatting turns a dense block into something you can read line by line.

That matters when you need to spot a missing bracket, a bad quote, or a value that does not match the shape you expected. The faster you can see the structure, the faster you can fix the issue.

Common JSON mistakes

Trailing commas after the last item in an object or array
Single quotes instead of double quotes for keys and strings
Missing brackets, braces, or a closing quote inside a string
Comments pasted from JavaScript into pure JSON
Escaping problems inside nested text values

If the output still looks wrong after formatting, check the outer structure first. Most JSON errors come from one small syntax issue near the top or inside the deepest nested block.

When to format, and when to minify

Use formatted JSON when you are reading data, comparing responses, or explaining an issue to someone else. Indentation makes nesting obvious, so arrays and objects are much easier to scan.

Use minified JSON when size matters more than readability. That is useful for sending payloads, storing compact sample data, or preparing responses for transport. The structure is the same either way, but the visual presentation serves a different goal.

For the cleanest workflow, format first, validate the shape, and only then minify if you need the smaller version.

Read the JSON API formatting guide →

FAQ

Does this tool keep my JSON?
No, the formatter runs in your browser so you can work locally.

What if my JSON is invalid?
The formatter helps you surface the syntax issue faster, which is usually the real problem.

Can I change indentation?
Yes, choose 2 spaces or 4 spaces depending on your preferred style.

Need more help?
Open the JSON formatter guide →