JSON Formatter
Format, indent, and validate JSON entirely in your browser.
Runs entirely in your browser.
Your data never leaves this device and is never sent to our servers.
Formatted JSON
Minified JSON is written for machines. One line, no spacing, and a missing comma buried three hundred characters in. This formatter re-indents it so you can actually read the structure, and tells you exactly where it breaks if it will not parse.
Common uses: inspecting an API response, tidying a config file before committing it, or checking that a payload you are about to send is well formed.
How to use it
- Paste your JSON into the input box.
- Choose an indent width — two spaces, four spaces, or a tab.
- Tick “Sort keys” if you want a stable, comparable ordering.
- Read the formatted output, then copy or download it.
Not working as you expect? Report a problem with this tool.
Frequently asked questions
Is my JSON sent to your server?
No. The formatting runs in your browser using the built-in JSON parser. Nothing is uploaded, logged, or stored, so it is safe to paste production payloads.
Why does my JSON fail to parse?
The three usual causes are a trailing comma after the last item, single quotes instead of double quotes, and unescaped line breaks inside a string. The error message names the position where parsing stopped.
What does sorting keys do?
It orders object keys alphabetically at every level. That makes two versions of the same document directly comparable in a diff, which is useful when you are trying to spot what changed.
Can it handle very large files?
Yes, within your browser memory. Multi-megabyte documents work, though the browser will feel slow above roughly 10 MB.