Developer tools
JSON formatter
Paste JSON below to validate it and explore it as a collapsible tree - fold or unfold any object or array, then copy it back prettified or minified. Everything runs in your browser - nothing is uploaded.
How it works
Paste JSON on the left and the formatter renders it on the right as a collapsible tree, syntax highlighted and easy to scan. Fold any object or array down to a one-line summary so you can focus on the part you care about, then unfold it again, or expand and collapse the whole document at once. If the input is not valid JSON it tells you what went wrong and exactly where, so you can fix a stray comma or missing bracket without hunting line by line.
Everything runs in your browser using the native JSON parser, so your data never leaves your machine and nothing is sent to a server. Copy the result back out whenever you need it: prettified with 2-space, 4-space, or tab indentation, or minified down to the smallest valid JSON, with a note of how many bytes you saved.
Example. Paste {"name":"Ada","skills":["math","code"]} and Format renders it as a tree you can fold and unfold. Collapse the "skills" array to a single line while you read the rest, then hit Minify and Copy to grab a compact single-line version ready to drop into a request body.
FAQ
Is my JSON sent anywhere?
No. Formatting, validating, and minifying all happen locally in your browser with the built-in JSON parser. Nothing is uploaded, logged, or stored on a server, so it is safe to paste sensitive payloads.
What is the difference between format and minify?
Both render the same collapsible tree; they change what Copy gives you. Format (prettify) copies the JSON with indentation and line breaks so the structure is easy to read. Minify copies the opposite: every unnecessary space and newline removed to produce the smallest valid JSON, which is what you want for transport or storage, along with the bytes you saved.
Why does it say my JSON is invalid?
The native parser rejects anything that is not strictly valid JSON: trailing commas, single quotes, comments, or unquoted keys are all common causes. The error message points to the line and column where parsing failed so you can jump straight to it.
Can I choose the indentation?
Yes. Pick 2 spaces, 4 spaces, or a tab, and Copy uses that for every level of nesting when it copies the prettified JSON. The choice only affects the copied output; the tree view nests visually on its own, and minify always strips indentation entirely.