JSON formatter and validator.
Paste JSON to pretty-print, minify, or find the exact syntax error with a line number. Runs entirely in your browser, no signup.
01 Format, validate, share
- Pretty-print instantly: 2 spaces, 4 spaces, tabs, or one-line minified.
- Real validation: invalid JSON shows the exact error with line and column.
- Private: everything runs in your browser, nothing is uploaded unless you publish.
- Share it: publish the result as a clean, readable live page in about two seconds.
02 Frequently asked questions
How do I format JSON online?
Paste your JSON into the editor above and it is pretty-printed instantly, no signup. Pick the indentation you want, or Minified to compact it.
Does this validate my JSON?
Yes. If the JSON is invalid you get the exact error with a line and column number so you can fix it fast.
Is my JSON uploaded anywhere?
No. Formatting and validation run entirely in your browser. Nothing leaves your machine unless you click Publish.
Can I share the formatted JSON as a link?
Yes. Click Publish and yapp.page hosts your formatted JSON as a readable live page you can share.
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