JSON Formatter

Pasted a wall of minified JSON from an API response and can't read it? This free JSON formatter pretty-prints it with the indent you choose — 2 spaces, 4 spaces or a tab — so nested objects and arrays become easy to scan. It also validates as it formats, so a missing comma or an unclosed bracket is flagged instead of silently ignored.

Everything runs in your browser: your JSON is never uploaded, which matters when it contains API keys, customer data or internal IDs. Developers often pair this with the Base64 Encoder when a payload hides encoded values, or grab a fresh test ID from the UUID v4 Generator before pasting a request body here.

What is JSON?

JSON (JavaScript Object Notation) is the text format almost every web API speaks. It builds everything from two structures: objects — curly braces holding named key-value pairs — and arrays — square brackets holding ordered lists. Values can be strings, numbers, true or false, null, or another object or array nested inside.

Pretty-printing vs minifying

Pretty-printing adds line breaks and indentation so humans can read the structure; minifying removes all unnecessary whitespace so machines can send it faster. The data is identical either way — only the layout changes. This tool lets you switch between the two without re-pasting.

Why sorting keys helps

Sorting keys alphabetically makes two versions of the same object easy to compare line by line, which is handy when diffing API responses or config files. It does not change the meaning of the JSON: key order is not significant in JSON.

Common errors, and what they mean

JSON is stricter than JavaScript: keys must use double quotes, trailing commas are not allowed, and comments are not part of the format. When the formatter reports an error, it gives the line and column where the parser stopped, so you can jump straight to the problem instead of scanning the whole file.