JSON Formatter
Format, minify and validate JSON. Errors are marked on the exact line.
About this tool
Readable JSON in One Click
Paste an API response or a config file and get it indented, or squeeze it onto one line. If the JSON is broken, the error is shown with its line and column and underlined in the input.
How to use it
- Paste JSON, or drop a .json file.
- Click Format and choose 2 spaces, 4 spaces or tabs, or click Minify.
- Copy the result or download it.
Frequently asked questions
Is my data sent anywhere?
No. Every tool runs in your browser. Tokens, passwords and files are processed on your device and never uploaded.
Can I link to a tool?
Yes. Each tool has its own address, for example toolula.com/dev/regex-tester, and you can star tools to keep them at the top of the list.
Does the JWT decoder check the signature?
No. It decodes the header and payload and shows their dates; checking the signature needs the secret or public key.
Are the generated passwords and UUIDs random enough?
Yes. They come from the browser's cryptographic random generator (crypto.getRandomValues / randomUUID), the same source used for keys.