realjsonviewer
Strict RFC 8259 Checker

Online JSON Validator.

Strict syntax validation with character-exact line and column error reporting, visual code pointers, and friendly resolution hints.

Depth:
0 B0 lines0 nodes
Valid JSON

Common JSON Syntax Errors and Fixes

  • Trailing Commas: Trailing commas before closing braces } or brackets ] are illegal in standard JSON.
  • Single Quotes: Standard JSON requires double quotes "key": "value" for all keys and strings.
  • Unquoted Keys: JavaScript object literals allow unquoted keys like name: "John", but JSON strictly requires "name": "John".
  • Comments: Comments (// or /* */) are not permitted in standard JSON.

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Frequently Asked Questions.

Everything you need to know about using this JSON tool safely and efficiently.

How does the validator pinpoint errors?
The validator parses the input strictly against the RFC 8259 JSON standard. When an error occurs, it computes the exact line number, column index, and displays a code excerpt with a visual pointer directly below the problematic character.
Does the validator detect JSON5 or JavaScript object syntax?
Yes! If you paste JSON with comments, single quotes, unquoted keys, or trailing commas, the validator detects these patterns and provides specific suggestions explaining how to convert them into valid standard JSON.
Is there a file size limit for validation?
Because all validation runs client-side in your browser, you can validate multi-megabyte JSON payloads instantly without network latency.