Tools / JSON Formatter
JSON Formatter
Format, minify, and validate JSON right in your browser. Paste a blob, choose an indent, and get clean output — nothing is uploaded.
No valid JSON yet
// About this tool
JSON Formatter
This JSON formatter pretty-prints, minifies, and validates JSON entirely in your browser. Paste a blob, pick 1, 2, or 4-space indentation, and get clean, readable output you can copy straight back into your editor or a config file.
It also works as a validator: invalid JSON produces an error with the exact line and column, so you can find the stray comma or unquoted key without a round trip to a server.
Everything runs locally — your JSON is never uploaded, which makes the tool safe for configs, API responses, and payloads that contain sensitive values.
// When to use it
Format an API response for debugging
Paste a minified JSON response from curl or a browser and read it with proper indentation.
Validate a config file before committing
Catch a syntax error with its exact line and column before it breaks a pipeline.
Minify JSON for a payload or storage
Shrink a formatted blob down to a single line for embedding or saving space.
// Questions
Is my JSON uploaded to a server?
No. Formatting, minifying, and validation all happen locally in your browser. Nothing is sent anywhere.
What indentation options are supported?
1, 2, or 4 spaces. You can switch between them at any time and the output updates instantly.
Does it support JSON5, comments, or trailing commas?
No — this is strict JSON only. Comments, unquoted keys, and trailing commas are reported as syntax errors, which is the behavior you want for validating standard JSON.
Can it format huge files?
There is no imposed limit because nothing is uploaded; practical limits depend on your browser's memory.
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