JSON Formatter & Validator — Free
Format, validate, and minify JSON instantly. 100% in your browser — free, no sign-up, no upload.
- ✓Free
- ✓No sign-up
- ✓Runs in your browser — files never uploaded
- ✓No watermark
How to
- 1Paste your JSON — it is processed in your browser and never uploaded.
- 2Click Format to beautify, or Minify to compact it.
- 3If the JSON is invalid, read the error to find the problem.
- 4Copy the result.
What does a JSON formatter do?
It takes raw JSON and pretty-prints it with consistent indentation so it is easy to read, or minifies it to the smallest valid form. It also validates the JSON, pointing out where a missing comma, bracket, or quote breaks the structure.
How it works in your browser
Parsing, formatting, and validation all run locally with the browser's own JSON engine — your data is never sent anywhere. That means you can safely paste API responses, config, or anything sensitive without it leaving your device.
When to use it
Make a cramped API response readable, spot the exact line where invalid JSON fails, tidy up a config file before committing it, or minify JSON to save space in a request or file. It is a daily tool for anyone working with APIs.
Format vs minify
Formatting (beautifying) adds indentation and line breaks for humans; minifying strips all unnecessary whitespace for machines, making the payload smaller. Use format while reading or debugging, and minify for production or storage.
FAQ
Is my JSON uploaded?+
No. Formatting, minifying, and validation all run in your browser, so your data is never sent anywhere.
What is the difference between format and minify?+
Formatting adds indentation and line breaks for readability; minifying strips whitespace to make the payload as small as possible.
Will it tell me why my JSON is invalid?+
Yes. If the JSON cannot be parsed, you get an error pointing to the problem so you can find the missing comma, bracket, or quote.
Can I paste sensitive data?+
Yes. Nothing leaves your browser, so API responses and config are safe to paste.
Is it free?+
Yes, completely free — no sign-up and no watermark.
Is my data private?+
Yes — this tool runs entirely in your browser. Your files and text are never uploaded.