JSON Formatter
Beautify, minify, sort keys, and validate. Zero server.
JSON, instantly clean.
Beautify, minify, sort keys, explore as a tree, and validate in one view. Your input never leaves the browser.
Input
Output
Output appears here.
Format, minify, and validate JSON in one place
Paste any JSON and it is beautified instantly with 2-space, 4-space, or tab indentation. Switch to Minify to strip every space for the smallest payload, or Sort keys to reorder object keys alphabetically — handy for diffing two API responses that return keys in different orders.
Errors point to the line
When the JSON is invalid, the output shows the parser message and, where the browser provides it, the line and column of the first problem — usually a trailing comma, a missing quote, or a stray bracket.
Everything stays in your browser
All parsing runs locally with the native JSON engine. Nothing is uploaded, logged, or stored — safe for config files and API payloads that contain tokens.
FAQ
Why did a large number change after formatting?
JavaScript parses numbers as IEEE-754 doubles, so integers beyond 2^53 (like some Discord/Twitter IDs) lose precision. Keep very large IDs as strings in the source if exact digits matter.
Does it support JSON5 or comments?
No — it validates strict JSON (RFC 8259). Comments and trailing commas are reported as errors, which is what most APIs expect.
Is my data sent anywhere?
Never. Formatting happens entirely in your browser; there is no server round-trip.