JSON Tools

Format, validate, minify and beautify JSON in your browser. Every tool reports the exact line and column of a syntax error, and nothing is uploaded.

5 tools in this category.

JSON Formatter
Turn minified or messy JSON into clean, indented, readable output — and catch syntax errors while you are at it.
JSON Beautifier
Expand compressed JSON into a wide, readable layout — ideal for reading an API response you did not write.
JSON Minifier
Strip all whitespace from JSON to shrink API payloads and config files, with a byte-for-byte savings report.
JSON Validator
Check whether JSON is valid and get the precise line and column of any error, plus structural statistics.
JSON Schema Validator
Validate a JSON document against a JSON Schema and get every failure at once, each located by JSON Pointer.

About JSON Tools

Five tools that look similar and are not interchangeable. The JSON Formatter and JSON Beautifier both pretty-print, but the formatter re-serialises through a parser — so it normalises escapes and number formatting and fails loudly on malformed input, while the beautifier is the one to reach for when you want indentation applied and nothing else touched. The JSON Minifier strips insignificant whitespace for transport. The JSON Validator answers only "is this parseable, and if not, where", and the JSON Schema Validator answers the different and usually more useful question of whether a parseable document matches the shape your API promised.

The distinction that matters most in practice is between valid and correct. `{"id":"42"}` is valid JSON and wrong if your schema says `id` is an integer — no formatter will ever tell you that, because syntactically there is nothing to report. Validating against a JSON Schema is what catches the class of bug where a payload parses cleanly, passes straight through your code, and fails three services downstream. If you are debugging an integration rather than a syntax error, start at the Schema Validator.

Every one of these runs in your browser. That is a privacy property first — API responses routinely carry tokens, customer records and internal identifiers, and pasting one into a server-side formatter means handing all of it to a third party — but it is also why they stay fast on large files and work with no network at all.

Frequently asked questions

What is the difference between the JSON Formatter and the JSON Beautifier?

The formatter parses the document and re-serialises it, which normalises escape sequences and number representation and rejects anything malformed. The beautifier applies indentation while preserving the original tokens as closely as possible. Use the formatter to produce canonical output you will commit or compare; use the beautifier when you want to read a file without altering anything you did not intend to.

My JSON is valid but my API still rejects it. What now?

That is a schema problem rather than a syntax problem, and the JSON Schema Validator is the tool for it. Valid JSON only means the document parses; it says nothing about whether a field is the right type, whether a required property is present, or whether a string matches an expected format. A number sent as "42" instead of 42 parses perfectly and fails validation everywhere downstream.

Is there a size limit, and is my data uploaded?

Nothing is uploaded — every JSON tool here runs entirely in your browser, so the practical limit is your available memory rather than a server quota. Files in the low tens of megabytes are routine. Because the work is local, a document containing credentials or customer data never leaves your machine, which is not something a server-side formatter can offer whatever its privacy policy says.

Should I minify JSON before storing it in a database?

Usually not. Most databases with a native JSON type parse and store their own internal representation, so whitespace in your input is discarded regardless and minifying first buys nothing. Minification is worth it for network transport and for columns typed as plain text, where the bytes you send are the bytes that get stored.

Other categories