---
title: "Sync vs. async exceptions in Node.js?"  
description: "Sync vs. async exceptions in Node.js?"  
author: "Utpal Vishwas"  
published: 2023-08-03  
updated: 2023-08-04  
canonical: https://www.mindstick.com/forum/159443/sync-vs-async-exceptions-in-node-js  
category: "node.js"  
tags: ["exception handling", "javascript", "node js"]  
reading_time: 2 minutes  

---

# Sync vs. async exceptions in Node.js?

Sync vs. [async](https://www.mindstick.com/forum/23036/calling-an-activity-class-from-async-class) [exceptions](https://www.mindstick.com/interview/22871/define-predifined-generic-exceptions) in [Node.js](https://www.mindstick.com/articles/1499/upload-and-download-file-in-node-js)?

## Replies

### Reply by Aryan Kumar

In Node.js, there are two types of exceptions: sync and async.

- **Sync exceptions** are thrown immediately when they occur. This means that the execution of the program will stop at the point where the exception is thrown.
- **Async exceptions** are not thrown immediately. Instead, they are queued up and handled later. This means that the execution of the program will continue after the exception is thrown.

The main difference between sync and async exceptions is how they are handled. Sync exceptions are handled immediately, while async exceptions are handled later. This can have a significant impact on the performance of your program.

In general, you should use sync exceptions for errors that are critical and need to be handled immediately. For example, if you are trying to connect to a database and the connection fails, you should throw a sync exception. This will prevent the program from continuing until the database connection is restored.

You should use async exceptions for errors that are not critical and can be handled later. For example, if you are making a request to an API and the request fails, you should throw an async exception. This will allow the program to continue while the request is retried.

Here is an example of a sync exception:

```plaintext
try {
  // This code will throw a sync exception if the database connection fails.
  connectToDatabase();
} catch (err) {
  console.log(err);
}
```

Here is an example of an async exception:

```plaintext
try {
  // This code will throw an async exception if the API request fails.
  makeApiRequest();
} catch (err) {
  // Handle the exception later.
}
```


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Original Source: https://www.mindstick.com/forum/159443/sync-vs-async-exceptions-in-node-js

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