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JSON formatter
Validate, format and minify JSON to make it easier to read and use.
Uses the browser's JSON parser. Numbers greater than 2⁵³ − 1 may lose precision: represent large identifiers as strings. Duplicate keys keep only the last value.
JSON formatter: how it works
Valid JSON is the starting point for working with APIs, configuration files and structured data. This tool adds indentation for readability or removes unnecessary whitespace for a compact version.
- Paste the JSON you want to check. You can load an example to try it out.
- Choose Format for two-space indentation or Minify for compact output.
- Copy the result or download it as a .json file.
Frequently asked questions
What errors can it detect?
It detects invalid syntax, such as trailing commas, missing quotes and unclosed braces, using the browser parser. It does not validate a JSON schema or business rules.
Does it change the data?
It rewrites the JSON representation. Duplicate keys keep only the last value, and very large numbers may lose precision. Store those identifiers as strings.