JSON Formatter & Validator
Pretty-print, validate, and minify JSON instantly.
100% in your browser — nothing uploadedPaste any JSON and get a clean, indented version with syntax validation. If the JSON is invalid, the exact error and position are shown so you can fix it fast. You can also minify — stripping all whitespace for compact payloads.
Everything happens locally in your browser using the native JSON parser. Your data never leaves your device, which makes it safe for API responses, config files, and anything containing credentials or customer data.
FAQ
Is my JSON uploaded to a server?
No. Formatting and validation run entirely in your browser with JavaScript. Nothing is sent anywhere.
What does "minify" do?
It removes all unnecessary whitespace and line breaks, producing the smallest valid version of your JSON — useful for APIs and storage.
Why is my JSON invalid?
Common causes: trailing commas, single quotes instead of double quotes, unquoted keys, or comments (standard JSON allows none of these). The error message points to the exact position.