JSON validate, format and shrink

Find syntax errors before further processing

JSON is used for API responses, configurations and data exports. A missing comma, an unclosed quotation mark or an additional comma at the end can prevent processing. The validator checks the syntax and shows the browser error message. Comments and simple quotes do not belong to the JSON standard and are not silently corrected.

Receive large numbers and double keys

Usually reading and rewriting with JavaScript, large integers can be rounded. This formatter validates with the parser, but creates the output from the original text tokens. Numbers such as 9007199254740993 and their spelling are therefore preserved. Duplicate object keys are counted and displayed as a warning. They are not deleted because different applications can interpret such data differently.

Formatting or minimizing

The formatted output uses two spaces per level. The compact mode removes insignificant spaces without changing characters within strings. Nested objects and arrays remain in their order. You can paste up to 500 KB of UTF-8 or open a file locally, copy the result and download it as JSON. More than 150 levels are rejected to limit processing.

Syntax does not have the same technical validity

Valid JSON may still contain the wrong fields, values or data types for your application. The tool does not validate a JSON schema and does not check API contracts. Also, a JSON-LD document needs additional rules so that search engines understand the described data. The basis of JSON syntax is RFC 8259.

Frequent questions