Format, minify, and validate JSON.
Paste messy or broken JSON below. Format it with clean indentation, squash it with Minify, or just check that it's valid — all processed right here in your browser, nothing ever uploaded.
Good to know
Does this check my JSON against a schema?
No. This only validates JSON syntax — balanced brackets, double-quoted keys, no trailing commas, and so on. It has no idea whether the fields, types, or structure match a particular schema or API contract.
Why does it say my JSON is invalid when it looks fine?
Strict JSON is pickier than a JavaScript object literal: keys must be wrapped in double quotes, trailing commas aren't allowed, and comments aren't part of the spec. The error message includes the line and column where parsing broke down — that's usually the fastest way to spot the problem.
Is my JSON uploaded anywhere?
No. Formatting, minifying, and validation all run with JavaScript in this browser tab. Nothing you paste here is ever sent to a server.
Is there a size limit?
There's no hard limit, but extremely large documents (many megabytes) can take a moment to process. If it seems stuck, try a smaller sample.