Why JSON validation matters
JSON powers APIs, app configs, dashboards, automation tools, and website structured data. One missing comma or quote can break an import, crash a script, or make schema markup invalid.
Common JSON errors
The most common JSON mistakes are trailing commas, single quotes, missing closing brackets, unescaped line breaks, duplicate keys, and comments pasted from JavaScript examples. A validator catches these problems before deployment.
How to validate JSON online
- Open the JSON Validator.
- Paste your JSON object, array, API response, or config snippet.
- Run validation and read the error location.
- Format the file with JSON Formatter for easier review.
- Test the cleaned JSON in your app or CMS.
API and config use
Developers should validate payloads before sending them to APIs. Marketers and SEO teams should validate JSON-LD before adding structured data to pages.
Structured data notes
Valid JSON is only the first step. For schema markup, also confirm that the property names match Schema.org expectations and that URLs, dates, and organization details are accurate.
Frequently Asked Questions
Read answers to the most common questions about this format and conversion process:
Yes. Paste JSON into the JSON Validator to check whether it is valid.
No. JSON does not allow trailing commas after the last item.
No. JSON strings and keys must use double quotes.
Yes. Use JSON Formatter to make valid JSON easier to read.