JSON validator
Invalid JSON breaks APIs, config deploys, and CI pipelines — often with vague "Unexpected token" messages. Paste or upload JSON to get immediate syntax validation with error location. Parsing runs locally; secrets in config files never hit a server.
How to validate JSON
1. Paste JSON into the editor or upload a .json file.
2. Read validation result: valid or error with position.
3. Fix trailing commas, quotes, or bracket mismatches.
4. Copy corrected JSON or send to formatter/minifier.
Validation examples
API response debug
Log output truncated mid-object — validator shows exactly where the string cut off.
package.json fix
Extra comma after last dependency block — validator points to line before npm install fails.
Webhook payload
Confirm third-party POST body is valid JSON before mapping fields in code.
When to validate JSON
• Before committing config to git or deploying to production.
• When debugging 400 Bad Request from malformed client body.
• When merging hand-edited JSON from non-technical teammates.
Strict JSON vs JavaScript
JSON is stricter than JS object literals — no comments, no undefined, no trailing commas. Copying from JS configs often breaks until cleaned.
Frequently asked questions
Common JSON mistakes?
Trailing commas, single quotes instead of double, unquoted keys, and missing commas between properties.
Does it validate schema?
Syntax only — structure against a schema is separate.
Large files?
Very large JSON may slow the browser — split or use streaming CLI tools for GB files.
Unicode and escapes?
Valid JSON requires \uXXXX for some controls; validator accepts UTF-8 in strings.
After fixing?
Use JSON formatter for readable layout or minifier for production.