JSON Formatter & Validator
Paste JSON, get it pretty-printed or minified — with the exact line and column when something's broken. Everything stays on your device.
Paste JSON to begin.
Is my JSON uploaded anywhere?
No. Parsing runs in your browser with the built-in JSON engine — nothing is sent, logged or stored. Safe for API keys, customer data and internal payloads.
Why do I get an error at a specific line?
The validator reports the exact line and column where parsing failed — usually a trailing comma, a missing quote, or single quotes instead of double quotes.
What's the size limit?
There is no hard limit; files of several megabytes format instantly since nothing travels over the network.