JSON Formatter and Validator

About JSON Formatter and Validator

JSON from APIs and config files is often squeezed into one line and hard to read. Paste it and this tool formats it with 2 or 4 spaces, minifies it or checks that it is valid and shows the error if not. Developers and analysts use it to inspect data. Everything runs in your browser, but avoid pasting secrets.

Example

Input: {"name":"USA AI Tools","tools":100}. Output: a formatted version with each key on its own line.

Tips for better results

• Check for missing commas or quotes if validation fails.
• Use minify before sending data to save bytes.
• Remove passwords and tokens first.

When to use JSON Formatter and Validator

Reach for this tool whenever a block of JSON is too dense to read or you need to know why a parser rejects it. Front-end and back-end developers, QA testers, analysts who export data from APIs, and support staff reading webhook payloads all run into this. It is especially handy while debugging a response from a service you do not control, tidying a config file before committing it, or checking that hand-edited data is still valid before an app tries to load it.

Real-world uses

• A developer pastes a one-line API response from a failing request and expands it to spot the field that came back null instead of a string.
• A QA tester hand-edits a sample payload for a bug report and validates it so the attached JSON does not contain a stray comma.
• An analyst receives a nested export from a web tool and formats it with indentation to see which keys hold the numbers needed.
• A site owner edits a theme or plugin settings file and checks it parses correctly before uploading it back to the server.

Common mistakes to avoid

• Using single quotes or unquoted keys, which many languages accept but strict JSON does not. Double quotes are required around every key and every string value.
• Leaving a trailing comma after the last item in an object or array. It looks harmless but makes the whole document invalid.
• Assuming valid means correct. The tool checks syntax only, so wrong field names, missing keys and wrong value types still need checking against your schema.

Format, minify and validate JSON. It works instantly in your browser, so there is nothing to install and nothing to upload. JSON Formatter and Validator is part of our collection of 100 free tools in the Developer & Data category.

How to use it

1. Enter your information or choose a file in the tool above.
2. Your result appears right below the tool.
3. Copy the result, or adjust your input and try again.

Want a deeper guide? Read What Is JSON? A Beginner's Guide with a Free Formatter.

Frequently asked questions

Does formatting change my data?

No. Formatting only adds or removes whitespace and line breaks. Keys, values and their order stay the same, so the formatted and minified versions represent exactly the same data when parsed by an application.

Can it handle comments in JSON?

Standard JSON does not allow comments, so a file with // or /* */ notes will be reported as invalid. Remove the comments first, or use a format built for them such as JSONC in your editor.

Is JSON Formatter and Validator free to use?

Yes. JSON Formatter and Validator is completely free and you do not need to create an account.

Is my data uploaded anywhere?

No. This tool runs in your browser, so what you type or choose stays on your device.

How accurate are the results?

Calculations use standard formulas, but always double-check important figures, especially for money, health or legal decisions.