How to use the JSON Validator
- 1
Paste the JSON you want to check.
- 2
Validation runs automatically as you type.
- 3
If there is an error, click “Go to error” to highlight the problem location.
- 4
Once valid, review the structure summary: type, depth, objects, arrays and keys.
Features & benefits
Line & column errors
Pinpoints the exact location of syntax errors with a snippet of the surrounding text.
Helpful hints
Explains common mistakes such as trailing commas, single quotes and unquoted keys.
Structure statistics
Shows nesting depth and counts of objects, arrays, keys and values.
Strict RFC 8259
Validates against the official JSON standard used by APIs everywhere.
The most common JSON mistakes
JSON looks like JavaScript, but it is stricter. Keys must be wrapped in double quotes, strings cannot use single quotes, trailing commas after the last item are not allowed, and comments are not part of the standard.
Other frequent issues include unescaped line breaks inside strings, special values like NaN or undefined, and copy-pasted “smart quotes” from word processors. The validator flags each of these with a clear message.
Frequently asked questions
Does it support JSON with comments (JSONC)?
No — comments are not valid in standard JSON, so they are reported as errors. Remove them before using the JSON with an API.
What is the difference between the validator and formatter?
The validator focuses on diagnosing errors and describing structure; the formatter rewrites valid JSON with nicer indentation or minifies it.
Is an empty string valid JSON?
No. Valid JSON must contain at least one value, such as an object, array, string, number, true, false or null.