Is my JSON uploaded anywhere?

No. Formatting and validation use your browser's built-in JSON parser, so API responses, configuration files and tokens you paste never leave your device.

Why does my JSON show an error about an unexpected token?

The most common causes are a trailing comma after the last item, single quotes instead of double quotes, unquoted property names, or comments. JSON allows none of these. The error message shows the line and column so you can jump straight to the problem.

What is the difference between formatting and minifying JSON?

Formatting adds indentation and line breaks so humans can read the structure. Minifying removes all unnecessary whitespace to make the payload as small as possible for network transfer or storage. Both produce exactly the same data.

Why would I sort JSON keys?

Sorting keys alphabetically makes two JSON documents easy to compare in a diff tool and keeps configuration files consistent in version control. The order of keys does not change the meaning of a JSON object.

JSON Formatter & Validator (Free, Private)

How to format and validate JSON

Paste your JSON into the input box, for example an API response or a config file.
Choose the indentation and whether to sort keys, then press Format.
If the JSON is invalid, the error shows the exact line and column. Fix it and format again.
Use Minify to get the smallest version for requests or environment variables.

Common JSON mistakes

Trailing commas: {"a": 1,} is invalid; remove the last comma.
Single quotes: strings and keys must use double quotes: {"name": "x"}.
Comments: standard JSON has no comments. Use JSONC or YAML if you need them.
Special values: NaN, Infinity and undefined are not valid JSON values.

When to use JSON vs YAML

JSON is the standard for APIs and data exchange because every language can parse it quickly and the rules are strict. YAML is friendlier for hand-edited configuration such as Kubernetes manifests and GitHub Actions workflows, but its indentation rules cause subtle bugs. Many teams write YAML and validate the result as JSON in CI.

How to format and validate JSON

Paste your JSON into the input box, for example an API response or a config file.

Choose the indentation and whether to sort keys, then press Format.

If the JSON is invalid, the error shows the exact line and column. Fix it and format again.

Use Minify to get the smallest version for requests or environment variables.

When to use JSON vs YAML

JSON Formatter & Validator

How to format and validate JSON

Common JSON mistakes

When to use JSON vs YAML

Frequently Asked Questions

Frequently Asked Questions

More free tools

JSON Formatter & Validator

How to format and validate JSON

Common JSON mistakes

When to use JSON vs YAML

Frequently Asked Questions

Frequently Asked Questions

More free tools