Format, validate, and minify JSON instantly with a browser-first editor.
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The ByteKiln JSON Formatter parses your input using the browser's native JSON.parse() function, then re-serializes it with JSON.stringify() using 2-space indentation. Formatting runs in your browser; your JSON is not sent to a ByteKiln server.
Formatting parses JSON and adds whitespace and indentation to make objects and arrays readable. Ordinary JSON values retain their meaning, but JavaScript number precision and duplicate-key handling can change some inputs; inspect the limitations below.
The sort keys option reorders all object properties alphabetically at every nesting level. Use it when comparing two JSON snapshots, normalizing API response shapes, or preparing configs for version control diffs.
Minifying removes all whitespace to produce the smallest possible output — useful for query strings, database columns, or API payloads where byte size matters. Format for readability; minify for transmission.
The formatter uses JSON.parse and JSON.stringify, not a lossless JSON parser. An integer such as 9007199254740993 becomes 9007199254740992 because it exceeds JavaScript safe-integer precision. Duplicate keys such as {"id":1,"id":2} keep the last value. Store exact large identifiers as strings, and check duplicate keys before relying on a formatted payload. Syntax validation also does not establish that a payload matches an API schema.
Short answers for the things developers usually ask before trusting a tool.
No. JSON parsing and formatting run in your browser; ByteKiln does not upload or log your payload for processing. Website resources and page analytics are separate. Optional share links contain your input and output; see the Privacy & Sharing page for details.
Yes. Invalid JSON produces a detailed error message with the line and column number where parsing failed, rather than silently producing broken output.
Formatting (pretty-printing) adds whitespace and indentation to make JSON human-readable. Minifying removes all unnecessary whitespace to produce the smallest possible output, which is useful for APIs and configuration values.
The formatter handles files up to several megabytes in the browser. Performance depends on your device, but typical API responses and configuration files process instantly.
Yes. The sort keys option reorders all object keys alphabetically at every nesting level, which is useful for diffing configurations and normalizing API snapshots.
Useful follow-ups when one conversion usually turns into three more.
Compare two JSON documents semantically: key order ignored, big numbers exact, arrays by position or by key, ignore paths, and export an RFC 6902 JSON Patch.
Convert JSON payloads into C# classes with nested types, arrays, DateTime, and Guid detection.
Generate CREATE TABLE scaffolding from JSON objects with nested structures and arrays.
Want the background and worked examples? There's a longer write-up.
Read the JSON Formatter guide