---
title: "What is the difference between synchronous postback and asynchronous postback?"  
description: "What is the difference between synchronous postback and asynchronous postback?"  
author: "Sumit Kesarwani"  
published: 2014-09-02  
updated: 2020-09-21  
canonical: https://www.mindstick.com/interview/2115/what-is-the-difference-between-synchronous-postback-and-asynchronous-postback  
category: "asp.net"  
tags: ["asp.net"]  
reading_time: 1 minute  

---

# What is the difference between synchronous postback and asynchronous postback?

The difference between synchronous and asynchronous postback is as follows:

Asynchronous postback renders only the required part of the page; whereas, synchronous postback renders the entire page for any postback.

Asynchronous postback executes only one postback at a time, that is, if you have two buttons doing asynchronous postback, the actions will be performed one by one; whereas, synchronous postback executes all the actions at once.

Asynchronous postback only modifies the update panel that raises the postback; whereas, synchronous postback modifies the entire page.

## Answers

### Answer by Sumit Kesarwani

The difference between synchronous and asynchronous postback is as follows:

Asynchronous postback renders only the required part of the page; whereas, synchronous postback renders the entire page for any postback.

Asynchronous postback executes only one postback at a time, that is, if you have two buttons doing asynchronous postback, the actions will be performed one by one; whereas, synchronous postback executes all the actions at once.

Asynchronous postback only modifies the update panel that raises the postback; whereas, synchronous postback modifies the entire page.


---

Original Source: https://www.mindstick.com/interview/2115/what-is-the-difference-between-synchronous-postback-and-asynchronous-postback

Copyright © MindStick Software Pvt. Ltd. This Markdown version is provided for developers, AI systems, and offline reading.