JSON formatter & validator
Beautify, minify and validate JSON right in your browser. Nothing is uploaded.
Files are processed in your browser and never uploaded.
How to use JSON formatter & validator
Add your text
Type or paste your text into the input box. Everything is handled by your own browser, so nothing is sent to a server.
Set the options
Choose Sort keys. The options are visible from the start, not hidden until you paste something.
Read it and keep a copy
The output updates as you type, so there is nothing to submit and nothing to wait for. Copy result, Don puts the result on your clipboard and Download .json saves it as a file.
What this tool does
Beautify and minify JSON
Beautify expands the JSON with proper indentation and Minify strips every space, so the same box handles reading it and shipping it.
Strict validation with clear errors
Invalid JSON is rejected with the reason and the position, which is usually a trailing comma or a missing quote rather than anything subtle.
Sort keys alphabetically
Sort keys puts the object keys in alphabetical order, which makes two versions of the same payload comparable.
2, 4 or tab indentation
Indent with 2 spaces, 4 spaces or tabs, so the output matches whatever the rest of the project uses.
Works offline, no sign-up
The parsing happens in your browser, so an API response with real data in it is never uploaded.
Frequently asked questions
Is my JSON uploaded anywhere?
No. It is parsed and formatted entirely in your browser, so even sensitive data stays on your device. It works offline once loaded.
What does it check when validating?
It uses the browser's strict JSON parser, so it flags trailing commas, missing quotes, unbalanced brackets and other errors, and shows the exact message describing the problem.
What is the difference between Beautify and Minify?
Beautify adds indentation and line breaks so the JSON is easy to read, while Minify removes all unnecessary whitespace to make it as small as possible.
Can it sort the keys?
Yes. Turn on Sort keys to order every object's keys alphabetically, which makes large objects easier to scan and compare.
Is there a size limit?
No fixed limit, though very large JSON is processed in your browser and may be slower on an older device.
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