Fix

Fix JSON Unexpected Token Error

Unexpected token errors indicate the parser encountered something that isn't valid JSON syntax at a specific position.

Open JSON Validator

Common Causes

UTF-8 BOM at file start, JavaScript comments (// or /* */), undefined/NaN/Infinity values, hex numbers (0xFF), trailing commas, or non-JSON content (XML, YAML).

Diagnosis

The JSON Validator shows the exact line and column. Check for invisible characters, wrong file format, or JavaScript-specific syntax.

Prevention

Use JSON.stringify() to generate JSON from JavaScript objects. Never manually convert JS objects without a serializer.