JSON Formatter
Format, validate, and minify JSON online with syntax highlighting. Runs in your browser—your data never leaves your device. Get error line/column, copy or download output. Use with Base64 or URL Encoder/Decoder.
Paste JSON above and click Format or Validate only.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data format used for storing and exchanging data between systems. It uses key-value pairs and arrays, is easy for humans to read, and for machines to parse. JSON is language-independent and supported by virtually every programming language.
A JSON formatter helps you validate syntax, fix formatting, and make JSON readable (pretty print) or compact (minify). This tool runs entirely in your browser—your data is never uploaded to a server.
Common uses:
- APIs — REST APIs typically request and return JSON. Format responses for debugging or inspection.
- Config files —
package.json,tsconfig.json, and many app configs use JSON. - Data storage — Document stores (MongoDB) and NoSQL databases often use JSON-like structures.
- Logs and exports — Format exported data or log outputs to understand structure and spot errors.
JSON Formatter FAQ
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data format used for storing and exchanging data. It uses key-value pairs and arrays and is easy for humans to read and for machines to parse. APIs and config files often use JSON.
Why does my JSON show an error?
Common issues: missing commas between elements, trailing commas, unquoted keys, single quotes instead of double quotes, or invalid escape sequences. Use the Validation tab to see the error message and line/column when available.
What is the difference between pretty print and minify?
Pretty print adds indentation and line breaks so the structure is easy to read. Minify removes unnecessary whitespace to reduce file size for production or APIs. Use pretty for debugging and minify for payload size.
Does this tool send my JSON to a server?
No. Formatting and validation run entirely in your browser. Your JSON is not uploaded. Only when you click Share do we save the result temporarily (24h) so you can share a link.
Can I validate without formatting?
Yes. Click "Validate only" to check if the input is valid JSON and see any error message and location. The Output tab will not be updated until you click Format.
What is the difference between JSON and JavaScript object literals?
JSON requires double quotes for keys and strings; JavaScript allows single quotes and unquoted keys. JSON does not allow trailing commas, comments, or undefined. Valid JSON is valid JavaScript, but not all JavaScript object literals are valid JSON.
How do I fix "Unexpected token" errors?
Check for trailing commas after the last element in an array or object, unquoted keys, single quotes instead of double quotes, or invalid escape sequences in strings. The error message and line/column in the Validation tab help locate the problem.