Private JSON Formatter & Validator
The secure, offline JSON formatter. Beautify, validate, and minify JSON directly in your browser using client-side processing. Your API keys, tokens, and sensitive data never leave your device.
Formatted output appears hereSolveBar's JSON Formatter instantly beautifies, validates, and minifies JSON data in your browser. Paste raw or minified JSON to see it formatted with proper indentation, or validate it to catch syntax errors before they cause bugs in production.
Format vs minify — when to use each
Formatted JSON is easier to read and debug — ideal for development and code review. Minified JSON removes all whitespace to reduce file size, improving load times in production APIs and config files.
Common JSON syntax errors
The most frequent mistakes: trailing commas after the last item in an array or object, single quotes instead of double quotes, unquoted key names, and comments (not supported in standard JSON). The validator catches all of these.
JSON security and privacy
All formatting and validation runs locally using JavaScript's built-in JSON.parse(). Your data is never sent to a server, making it safe to format sensitive data like API responses containing tokens.
Frequently Asked Questions
Why is my JSON showing an error?
Common causes: trailing comma after the last element, single quotes instead of double quotes, missing quotes around key names, or a comment (JSON does not support comments).
What is the difference between JSON and JavaScript objects?
JSON requires double quotes around keys and string values, does not allow trailing commas, and does not support undefined, functions, or comments.
Can I format deeply nested JSON?
Yes. The formatter handles arbitrarily deep nesting, arrays of objects, mixed types, and null values correctly.