What Is JSON Validator?
Most JSON tools only tell you the document is broken. The JSON Validator explains why, where and how to fix it: one scanner walks your text and reports every recoverable problem it finds, each pinned to a line and column with a plain-English message such as a trailing comma, single-quoted key or stray text after the document. When the JSON is clean, a structure outline maps objects, arrays and key counts so you can sanity-check payloads at a glance before shipping or debugging an API response.
Who Uses the JSON Validator?
Backend and frontend developers use it to locate the exact offending character in config files, API fixtures and pasted payloads instead of guessing from a bare parse error.
How to Use the JSON Validator
- Drop a .json file or paste the text into the source box.
- Press Run Diagnostics and open the problem cards, each stamped with a line and column number.
- On a clean pass, read the structure outline and use Minify or Copy formatted.
Why Choose Our JSON Validator?
- Lists every detectable syntax problem, not just the first
- Plain-English messages for trailing commas, comments and bad quotes
- Structure outline with depth, key and array counts on success
Try the JSON Validator above — it is free, fast, and works on any device. Bookmark this page to return whenever you need it.