Free JSON formatter and validator
Paste JSON to tidy it up, shrink it, or find out why it will not work. If something is wrong you get the line and column, and a plain-English reason, such as a stray comma or single quotes.
What you paste never leaves your browser, and we cannot see it.
Get help with your website
Want us to fix this for you?
Tell us what the tool found and we will tell you what it takes to fix it. The first call is free.
Get tips like these by email
Practical advice on getting found, getting faster and getting more enquiries, plus news and offers about WPfoss products. No more than once a fortnight, and one click to leave.
Optional. You do not need to sign up to see your results.
Want us to fix this for you? The first call is free.
Formatting, minifying and validating JSON
JSON is easy to read when it is laid out with indents, and impossible to read when it arrives as one long line. Format puts every item on its own line. Minify does the reverse. Both also check that the JSON is correct, because a single misplaced character makes a whole file useless.
- Strict on purpose. JSON is stricter than the JavaScript it looks like: double quotes only, no trailing commas, no comments.
- Sort keys puts the names of every object in alphabetical order, which makes two versions of the same file easy to compare.
- Private. It all happens on your device.
Working on a site? Our URL encoder and decoder and Base64 encoder and decoder are just as quick.
Questions people ask
What is JSON?
A plain-text way to write down structured data: names with values, lists, numbers, true or false. Websites, apps and plugins use it to pass information to each other, and many settings files are JSON.
Why does my JSON say it is invalid?
The most common causes are a comma after the last item, single quotes instead of double quotes, a key that is not in quotes, and a comment. The red box shows the line and column of the first problem and, when it can tell, which of these it is.
What does minify do?
It removes every space and line break, so the data is as small as it can be. That is what you want when sending it over the internet. Format does the opposite, so a person can read it.
Is my data safe?
Yes. The formatting runs in your browser. Nothing you paste is sent to us or anyone else, so it is fine to use with private data.
Does it keep very large numbers exactly?
Numbers above about 9 quadrillion lose their last digits when a browser reads them, which affects every JSON tool that runs in a browser. If you handle long IDs, keep them as text in quotes.