JSON Formatter & Validator
Paste or upload JSON, get it validated and beautifully formatted — with exact error locations if something's broken. Runs entirely in your browser.
About this tool
Malformed JSON is one of the most common — and most annoying — sources of bugs: a missing comma, a trailing comma, an unquoted key, and the whole payload fails silently. This tool parses your JSON properly, tells you exactly where it broke (line and column) if it's invalid, and if it's valid, reformats it with the indentation and key order you choose.
Nothing is uploaded — parsing and formatting happen entirely in your browser.
How it works
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1
Paste or upload your JSON
Drop in a .json file, or paste the code straight into the box.
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2
Choose your options
Pick indentation (2, 4 spaces, tabs, or minified) and whether keys get sorted alphabetically.
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3
JSON gets validated
If it's invalid, you get the exact line and column where parsing failed. If it's valid, it's reformatted instantly.
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4
Copy or download
Copy the formatted JSON, or download it as a ready-to-use file.
FREQUENTLY ASKED QUESTIONS
You'll see exactly which line and column parsing failed at, along with the browser's own error message — no need to eyeball the whole file.
No — key order doesn't matter for how JSON is read by code. Sorting only makes it easier for a human to scan and diff.
It strips all whitespace and line breaks, producing the smallest possible valid JSON — useful for production payloads.
No. Everything runs locally in your browser — your data is never sent to a server.
Need more than a free tool?
If you're ready for a real project — website, branding, or something custom — let's talk.