JSON Formatter & Validator
Format, minify and validate JSON with clear error messages.
- Runs in your browser - nothing is uploaded
- Free, no sign-up
Formats, minifies and validates JSON. Invalid input gets the parser's own error message, including the character position, which is usually enough to spot the missing comma or bracket. Valid input gets a quick summary of key count and nesting depth.
Frequently asked
What happens if my JSON is invalid?+
You get the parser's own error message along with the character position, which is usually enough to find the missing comma, bracket or stray trailing comma.
Can it minify as well as format?+
Yes. Minifying strips every space and newline, which is what you want before putting JSON into a config value or a URL.
Is it safe to paste data with secrets in it?+
The parsing happens in your browser and nothing is sent to a server. That said, treat any tool with real credentials carefully - redact them first if you can.
Worth reading
Python vs JavaScript: Which Should You Learn First in 2026?Python or JavaScript in 2026? An honest, head-to-head comparison - which is easier, what each one builds, which pays well, and exactly which language you should learn first based on your goals.4 min read10 Free Online Tools That Replace Paid Software in 2026 (No Sign-Up, 100% Private)Stop paying for simple software. These 10 free online tools convert PDFs, compress images, format JSON and more - right in your browser, with no sign-up and no files uploaded to any server.5 min read