What does “Unexpected character in JSON” mean?

This error occurs when a JSON parser encounters an invalid or illegal character, such as unescaped quotes, special symbols, or encoding issues.

What causes unexpected character errors in JSON?

Common causes include unescaped quotation marks, invalid symbols, copy-paste issues, encoding problems, or malformed API responses.

How do I fix an unexpected character in JSON?

Paste your JSON into the fixer. The tool highlights invalid characters and helps you correct the syntax instantly.

Does this error happen in API responses?

Yes. Unexpected character errors often appear when API responses contain encoding issues or malformed JSON payloads.

Is my JSON data safe?

Yes. All JSON validation and fixing runs locally in your browser. Your data is never uploaded or stored.

Syntax Error Guide

JSON Unexpected Character Error – Meaning, Causes & Fixes

The JSON Unexpected character error occurs when a JSON parser encounters a character that is not allowed by strict JSON syntax. Even a single invalid character can break parsing completely.

Common error messages:

Unexpected character ' in JSON

Unexpected character , at position 42

Unexpected character / in JSON

Unexpected non-whitespace character

This page helps you understand why this error happens and how to fix it instantly.

Strict

Syntax Rules

Instant

Detection

Private

& Secure

Example: JSON Unexpected Character Error

Invalid characters instantly break JSON parsing

❌ Invalid JSON

{
  'name': 'Alice',
{

❌ Single quotes and trailing comma are not allowed

✅ Fixed JSON

{
  "name": "Alice"
}

✅ Valid JSON – no unexpected characters

What Is “JSON Unexpected Character”?

This error means the JSON parser found a character that does not belong to valid JSON syntax. JSON is extremely strict and does not allow comments, trailing commas, or single quotes.

❌ Single quotes

❌ Comments

❌ Extra text

How to Fix JSON Unexpected Character

1️⃣

Paste JSON

Paste broken JSON into the editor

2️⃣

Detect Characters

Tool highlights invalid characters

3️⃣

Fix & Validate

Auto-fix and get valid JSON

Frequently Asked Questions

What does JSON Unexpected character mean?

It means the parser encountered a character that violates JSON syntax rules.

Is this different from unexpected token?

Yes. Unexpected character refers to invalid symbols, while unexpected token usually refers to structural issues.

Can APIs cause this error?

Yes. APIs may return HTML, logs, or error messages instead of JSON.