Format, validate, or minify JSON in your browser. Find syntax errors and make nested data easier to inspect.
How to use
Paste JSON and choose the operation. Select indentation for formatting, or validate before passing data to another service.
Example
{"name":"Ada","active":true} is valid JSON. A trailing comma after true makes the object invalid.
FAQ
Will it accept JavaScript objects?
No. Keys and strings need double quotes. Comments, functions, and trailing commas are not JSON. Large numbers use JavaScript numeric precision.
Related tools
A practical task
When a response fails to parse, check the first and last characters before changing its contents. An HTML error page, a copied log prefix, or a trailing explanation is not JSON. Formatting cannot turn those unrelated wrappers into a valid API response.
Another useful question
Does Valid JSON mean the API will accept it?
No. The API can require specific keys, types, ranges, or authentication. Compare its schema after the syntax check succeeds.
Settings and formats
| Field | Values |
|---|---|
| Operation | Format (format); Validate (validate); Minify (minify) |
| Indentation | 2 spaces (2); 4 spaces (4) |
Details for interpreting the result
| Detail | Explanation |
|---|---|
| Strict JSON syntax | JSON needs double quotes around keys and string values. Objects use braces and arrays use square brackets. Comments and trailing commas belong to other formats, so remove them before treating a source as JSON. |
| Strings and values | The JSON string "12" differs from the number 12, and "false" differs from false. Type changes affect comparisons and imports. Keep identifiers as strings when their leading zeros or exact digits matter. |
| Numeric precision | JavaScript numbers cannot represent every large integer exactly. Long account numbers, order identifiers, and arbitrary precision decimals should remain strings or use a suitable numeric library in the receiving application. |
| Syntax and schema | A document can be syntactically valid yet contain the wrong fields or types for an application. Syntax checks confirm the format; schema and business rules determine if the receiving system can use the data. |
| Empty and missing data | An empty string, a missing property, and null express different states in structured data. A flat table can merge some of those distinctions. Confirm how missing cells should be handled before converting records. |
| Column headers | Headers provide names for columns; they are not extra data values. Keep their order aligned with each row. When building objects, duplicate header names create ambiguity about which value belongs to a key. |
| Source boundaries | A summary or rewrite works from the material you provide. A URL alone does not supply the full article in this interface. Include the relevant passage and keep citations attached to the claims they support. |