Free formatter
Format, validate, and inspect JSON — beautifully.
Paste your JSON, hit Format. Get instant beautification, line-and-column error markers, a clickable tree view, and 100+ keyboard shortcuts. Nothing is ever uploaded.
Runs entirely in your browser
Pretty + minify
Beautify with 0/2/4/8-space indent. One-click minify produces the smallest valid output.
Line/column errors
Invalid JSON? You see the exact line and column highlighted in the editor — same as VS Code.
JSON5 friendly
Comments and trailing commas are tolerated when strict JSON parsing fails.
Tree + diff
Click into nested values, search keys/values, compare two payloads side-by-side.
Privacy-first
Every operation runs in your browser. Open DevTools and verify — no API calls, no telemetry.
Keyboard-first
Ctrl+Enter to format, Ctrl+F to search, Ctrl+P for the command palette. Works offline.
FAQ
Is this really free?
Yes — no signups, no rate limits, no ads. Built and maintained by Yash Adake.
Does my JSON get uploaded anywhere?
No. Parsing, formatting, validation, diff, search — all happen locally in your browser. There is no backend.
How big a file can I paste?
Tens of megabytes work comfortably. The editor uses Monaco (the engine behind VS Code) and we debounce parsing so typing stays snappy.
Does it support JSON5 / JSONC (comments, trailing commas)?
Yes — strict JSON is tried first, and if it fails, JSON5 is used as a fallback so your tsconfig-style files just work.