JSON Formatter & Validator
Paste raw or minified JSON to instantly validate and pretty-print it with 2-space indentation. Toggle to minify mode to compact it back to a single line. If the input is not valid JSON, a clear error shows the exact position of the problem — no silent failures. Everything runs locally in your browser.
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Developer & WebAbout the JSON Formatter & Validator
The JSON Formatter uses JavaScript's native JSON.parse() to validate and parse your input, then JSON.stringify() with an indentation argument to produce readable output. Because JSON.parse() throws a SyntaxError with a descriptive message (including the character position of the problem), the tool surfaces this directly so you can pinpoint and fix malformed input — for example, a trailing comma after the last object key, an unquoted key, or a single-quoted string. Minify mode calls JSON.stringify() without indentation, producing the most compact valid representation. This is useful before embedding JSON in an API request body, storing it in an environment variable, or including it in a configuration file where whitespace adds unnecessary bytes. Developers frequently use a formatter when inspecting API responses copied from browser DevTools, debugging webhook payloads, or reviewing configuration files from CI/CD pipelines.
Why does my JSON fail to parse?▾
JSON has strict rules: keys must be double-quoted strings, trailing commas are not allowed, and single quotes are invalid. The error message shows the character position of the first problem to help you locate and fix it.
What is the difference between pretty-print and minify?▾
Pretty-print adds consistent 2-space indentation and newlines to make the structure readable. Minify removes all unnecessary whitespace to produce the smallest valid JSON string — useful for API payloads and storage.
Does this support JSON with comments (JSONC)?▾
No — standard JSON does not allow comments, and JSON.parse() will reject them. If you have JSONC (used in tsconfig.json), strip the comments before pasting, or use a dedicated JSONC parser.