JSON Viewer & Formatter
Format, validate, and explore JSON in a collapsible tree. It runs entirely in your browser, so the file never leaves your computer.
Why minified JSON exists, and why it hurts
JSON travelling over a network is stripped of every space and line break, because whitespace is bytes and bytes are latency. That is correct engineering and completely unreadable — a 4,000-character single line that your eye cannot find a foothold in.
Paste it here and it comes back indented, with a collapsible tree so you can shut the branches you do not care about and open only the part you are chasing. The minify option does the reverse when you need to send it back out tight.
Finding the character that broke it
"Unexpected token" is the least helpful error message in computing. The parser tells you where it gave up, which is often nowhere near where the mistake is.
This points at the spot and, more usefully, the usual suspects are a short list: a missing comma between two entries, a trailing comma after the last one (legal in JavaScript, illegal in JSON, and the single most common cause), or an unbalanced bracket or quote just above where it stopped.
Why the paste matters
JSON is where API keys, access tokens, customer records and config secrets live. A good proportion of the online JSON formatters are ad-funded, and some of them log what gets pasted in.
This one does the parsing in your browser. Nothing is transmitted, which is the only form of that promise you can verify yourself by disconnecting the network and watching it carry on working.
Questions
Common questions
What does this tool do?
It takes messy or minified JSON and makes it readable — neatly indented, with a collapsible tree view — and tells you if there's a syntax error and exactly where.
How do I use it?
Paste your JSON into the box. It formats it instantly and shows a tree you can expand and collapse. If the JSON is broken, it points to the spot that's wrong.
It says my JSON is invalid — how do I find the problem?
The tool locates the error and shows where it is. The usual culprits are a missing comma, an extra trailing comma, or unbalanced brackets or quotes near the spot it points to.
Can it make JSON smaller?
Yes — the minify option strips out all the spacing to produce the most compact version, which is what you want when sending JSON over a network or storing it tightly.
What's the tree view for?
Large JSON is hard to read as one block. The tree lets you collapse sections you don't care about and expand only the parts you're looking at, so you can navigate big structures easily.
Is my data private?
Yes. All formatting and validating happens on your own computer in the browser — nothing you paste is uploaded. Many online JSON tools are ad-walled or quietly log pasted content; this one doesn't.
Our own software
Dictate it instead of typing it
Hold a key, say the sentence, and the words land in whatever Windows window you were already in. Runs on your own PC — no account, no upload, nothing to renew.
$79 launch price · $99 regular · buy once