# How to Debug JS Errors Using ChatGPT(Beginner's Guide)

> Source: <https://dev.to/janani_jayakumar_fe8ab5ce/how-to-debug-js-errors-using-chatgptbeginners-guide-2f0o>
> Published: 2026-07-18 09:07:59+00:00

Everyone makes mistakes while coding. The good news is that AI tools like ChatGPT can help you understand and fix JavaScript errors faster.

In this blog, you'll learn how to use ChatGPT to debug common Javascript errors with real examples.

**Reference Error**

```
console.log(username);
```

**Output:**

```
ReferenceError: username is not defined
```

**Prompt to ChatGPT:**

Explain why I'm getting *ReferenceError: username is not defined in Javascript* and show me how to fix it.

**Solution:**

``` js
let username = "Janani";
console.log(username);
```

**TypeError**

``` js
const user = null;
console.log(user.name);
```

**Output:**

```
TypeError: Cannot _read_ properties of null (reading _'name'_)
```

**Prompt to ChatGPT:**

Explain this *TypeError* in simple words and provide the correct code.

**Solution:**

``` js
const user = null;
if(user) {
   console.log(user.name);
}
```

**SyntaxError**

```
if (true {
  console.log("Hello");
})
```

**Output:**

```
SyntaxError: Unexpected token '{'
```

**Prompt to ChatGPT:**

Find the *syntax error* in this code and explain it like I'm a beginner.

**Solution:**

```
if(true) {
  console.log("Hello");
}
```

**Undefined**

``` js
let age;
console.log(age);
```

**Output:**

```
undefined
```

**Prompt to ChatGPT:**

Why is this variable *undefined?* Explain with an example.

**Solution:**

``` js
let age = 25;
console.log(age);
```

**NaN**

``` js
let result = "Hello"*5;
console.log(result);
```

**Output:**

```
NaN
```

**Prompt to ChatGPT:**

Why am I getting *NaN*? How can I avoid it?

**Solution:**

``` js
let result = 10*5;
console.log(result);
```

Instead of asking:

My code is not working.

Ask:

I'm getting

TypeError: Cannot read properties of undefined. Here's my code. Explain the error in simple words and provide a corrected version.

The more context you give, the more accurate the AI's answer is likely to be.

AI doesn't just fix your code-it can help you understand why an error happened. Use it as a learning partner rather than simply copying the solution. Over time, you'll become much better at debugging on your own.