Debounce vs Throttling

Debounce vs Throttling


Debouncing and throttling are two techniques used to control the rate at which a function is executed. Both are essential in optimizing performance and improving user experience in web development, but they serve slightly different purposes.



Imagine a search bar that fetches suggestions from a server as the user types. If a request is sent to the server with every keystroke, it can lead to a significant load on the server and a laggy experience for the user. This is where debouncing comes in.


Debouncing is a technique that limits the rate at which a function can fire. A debounced function will only execute after a certain amount of time has passed without it being called again. In the context of the search bar, debouncing ensures that the server request is made only after the user has stopped typing for a predetermined period, say 300 milliseconds.

This means that regardless of the number of keystrokes, the function to get suggestions is called only once after the user stops typing. This reduces server calls and makes the performance and user experience better.



Think about a website where more pictures or messages load as you scroll down, similar to social media feeds. If the website tries to load more content every single time you move down even a little bit, it can make scrolling slow and choppy. This happens because the website is working too hard, trying to load more stuff every fraction of a second.


Throttling is like setting a timer for how often the website can try to load more content while you scroll. For example, you could set it up so the website only tries to load more pictures or messages once every 200 milliseconds (which is a fifth of a second) no matter how much you scroll.

This way, every 200 milliseconds, the website can only load more pictures once. This makes scrolling smooth because the website isn’t overloaded with work, and it still loads more content as needed without any noticeable delay.


Throttling makes a function run only once in a certain time frame, making sure it runs regularly but not too much.

Debouncing waits for a break in activity before running a function, delaying it until the triggers stop for a set time.

Throttling manages how often a function runs, while debouncing waits for the activity to stop before running it.