What is a JSON Validator?
A JSON validator checks whether JSON syntax is valid and whether a standard parser can read the complete document.
JSON Tools
JSON validation guideJSON Validator
Validate JSON instantly. Paste JSON, check syntax errors, view formatted output, and copy valid JSON.
JSON input
Paste an object, array, or any valid JSON value.
Validation result
Syntax status, diagnostics, and valid JSON output.
Ready to validate JSON
Paste JSON on the left or load a sample. Validation runs automatically after a short pause.
JSON Validation Guide
Validate JSON syntax before it reaches your application
Use the validator to find structural mistakes quickly, then copy clean formatted JSON once the document is valid.
How to use this JSON Validator
Paste JSON, click Validate JSON, review the valid or invalid status, fix reported syntax errors, and copy formatted JSON when validation succeeds.
Common JSON syntax errors
Trailing commas, single quotes, missing commas, unquoted property names, comments, extra closing braces, and incomplete strings commonly make JSON invalid.
JSON Validator vs JSON Formatter
Validation checks syntax correctness. Formatting makes valid JSON easier to read. This page focuses on validation and actionable error feedback first.
Why valid JSON matters
APIs, configuration files, package files, logs, webhooks, and database documents depend on predictable JSON syntax.
Private browser processing
Validation, formatting, minifying, summaries, and tree rendering happen locally in your browser. Your JSON is not uploaded.
JSON Validator FAQ
Is this JSON Validator free?
Yes, it is free to use.
Does this tool upload my JSON?
No. JSON validation runs locally in your browser.
What does a JSON Validator do?
It checks whether your JSON syntax is valid and can be parsed.
Can this tool fix invalid JSON automatically?
No. Version 1 detects and explains errors without silently rewriting invalid JSON. It formats JSON only after validation succeeds.
Why is my JSON invalid?
Common reasons include trailing commas, single quotes, comments, missing commas, unquoted keys, or incomplete braces.
Does JSON allow comments?
No. Standard JSON does not allow comments.
Does JSON allow trailing commas?
No. Standard JSON does not allow trailing commas.
What is the difference between JSON Validator and JSON Formatter?
A validator checks syntax correctness. A formatter makes valid JSON easier to read.