JTA
Parse Error Fixer

JSON Parse Error – How to Fix Invalid JSON Instantly

A JSON parse error occurs when your application tries to read JSON data that doesn't follow proper JSON syntax rules. Even a small mistake—like a missing comma or invalid quote—can cause errors.

Common error messages:

Unexpected token < in JSON
Unexpected end of JSON input
JSON.parse is not a function
Invalid or malformed JSON

This page helps you understand, detect, and fix JSON parse errors instantly using a free browser-based tool.

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Example: JSON Parse Error

See how we fix common JSON parse errors automatically

❌ Invalid JSON 

{
  "name": "John"
  "age": 30,
}

Problems:

  • •Missing comma after "John"
  • •Trailing comma after 30

✅ Fixed JSON 

{
  "name": "John",
  "age": 30
}
✅Valid JSON – No parse errors!

What Is a JSON Parse Error?

A JSON parse error happens when a JSON parser (such as JSON.parse() in JavaScript) encounters invalid JSON syntax.

JSON is very strict. Unlike JavaScript objects:

•Keys must be in double quotes
•Trailing commas are not allowed
•All brackets and braces must match

If any rule is broken, parsing fails.

Common JSON Parse Error Messages

Here are the most common parse errors and what causes them

1. Unexpected token

Unexpected token } in JSON at position 45

Cause: Extra or missing characters, commas, or brackets.

2. Unexpected end of JSON input

Unexpected end of JSON input

Cause: Missing closing brace } or bracket ].

3. Unexpected token < in JSON

Unexpected token < in JSON at position 0

Cause: API returned HTML instead of JSON (often an error page).

4. JSON.parse is not a function

JSON.parse is not a function

Cause: The variable you're parsing is not a JSON string.

How to Fix JSON Parse Errors (Step-by-Step)

1

Paste Your JSON

Paste the broken JSON into the input editor

2

Detect Errors

Tool highlights missing commas, invalid quotes, unclosed brackets

3

Auto-Fix JSON

Click Fix JSON to instantly correct syntax issues

4

Copy & Use

Copy the corrected JSON and use it safely

Common Causes of JSON Parse Errors

❌

Missing commas between properties

Forgot to add comma separator between object fields

❌

Trailing commas

Extra comma at the end of object or array

❌

Single quotes instead of double

JSON requires double quotes for strings

❌

Unmatched brackets

Missing or extra {} or []

❌

Copy-pasted from logs or emails

Hidden characters or formatting issues

❌

API returning HTML instead of JSON

Server error page sent as response

When Do JSON Parse Errors Occur?

You'll commonly see them when:

Calling JSON.parse()

Parsing JSON strings in JavaScript code

Fetching API responses

Reading data from REST APIs or web services

Loading config files

Application configuration or settings files

Parsing backend responses

Server-side data sent to frontend

Working with third-party APIs

Integrating external services

Why Use This JSON Parse Error Fixer?

✔ Instant Error Detection

Find exactly where your JSON breaks without manual debugging.

✔ Auto-Fix Common Issues

No manual debugging or guessing. Instantly fix syntax errors.

✔ 100% Client-Side

Your data never leaves your browser. Complete privacy guaranteed.

✔ Works for Any JSON

APIs, config files, logs, exports.

Frequently Asked Questions

What does “Unexpected token” mean in JSON?

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

Can JSON.parse fix errors automatically?

No. JSON.parse() only reads valid JSON. You must fix syntax errors first.

Is this tool safe for private data?

Yes. All processing happens in your browser.

Why does my API return a JSON parse error?

Often the API returns HTML (like an error page) instead of JSON.