Chrome extensions increase CPU usage and slow down browsing

Milan Stanojevic
by Milan Stanojevic
Deputy Editor
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Affiliate Disclosure

  • It is common knowledge that a Chrome browser filled with extensions will slow down your PC.
  • We've conducted our own study, and we will be presenting you our findings below.
  • To learn more about Chrome, check out our dedicated Chrome page.
  • If you want to know more about extensions, we also have a dedicated Extensions page.
chrome extensions slow browser

DebugBear recently analyzed 26 browser extensions to study their impact on browsing performance.

The test was carried out on some of the most popular extensions such as  Adblock Plus, uBlock, HTTPS Everywhere, LastPass, and Grammarly among many others.

The results should also help you if you are interested in the following:

  • Does Grammarly slow down your computer
  • LastPass slowing down Chrome
  • Grammarly slows down Chrome

Quick Tip

Google Chrome has a reputation when it comes to slowing down your PC by taking up most of your RAM and CPU. This is especially the case when you have extensions opened, and a few extra tabs on the side as well.

That is why we recommend you switch to another web browser: Opera GX. It is built using the same Chromium engine as Google Chrome, so all Chrome extensions are also compatible with Opera GX.

However, Opera’s low inherent system requirements make it far less impactful than Google Chrome, extensions installed or not. More so, it comes with a built-in CPU, RAM, and bandwidth limiter, so you can control your memory usage better.

Opera GX

Opera GX

Surf the Internet with the fastest web browser on the market, and don't worry about loading it with extensions, since it won't take up all of yoru RAM or CPU.

In case you want to be secure while surfing the internet, you will need to get a full-dedicated tool to secure your network.  Install now Private Internet Access and secure yourself. It protects your PC from attacks while browsing, masks your IP address and blocks all unwanted access.


Browser extensions may slow down Chrome

The conclusions of this analysis are not at all surprising. They confirm what many users already noticed. Namely, certain browser extensions may increase power consumption and even slow down your browser.

This happens because these extensions put a strain on your CPU. Let’s look at some numbers to see which extensions require your CPU to do more work.

ExtensionWhat is it?UsersExtra CPU time*
HoneyAutomatic coupon code finder10M+636ms
GrammarlyGrammar checker10M+324ms
Evernote ClipperSave web content to Evernote4.7M265ms
StayFocusdLimit time spent on websites700K224ms
LastPassPassword manager8M139ms

Things Chrome extension devs should consider

Chrome extension developers need to consider the following points in order to reduce the impact their products have on the browsing experience. Content scripts should be used on the domains as per the requirements.

Secondly, the content script should not be run on document_start. The developers should avoid overloading the code with JavaScript. As it can be loaded easily whenever you need to include the JS bundle. 

Main takeaways

The researchers have also mentioned some key findings of the study. The performance cost of the single extension can be small but the combined performance cost might add up to a significantly large value.

The performance can significantly be improved by using privacy tools in those cases when the website is overloaded with analytics or ads. 

The study also has some limitations as well, it has only considered just a single browser i.e Google Chrome. We have to extend the research to some other popular browsers as well to find out how the results vary with respect to each browser.

Furthermore, the sample size should be kept large by increasing the number of extensions in future experiments.

In short, the study revealed that Honey and Grammarly are extremely slow as far as the browsing performance is concerned.browser extension slow browsing

The power consumption is usually increased when you have so many extensions installed in your system. The extension developers should follow the best practices in order to avoid performance problems in future.

Privacy is a major concern these days in view of the recent cyber-attacks and data leaks by 3rd party apps and programs. Experts recommend that you should reduce the number of extensions installed in your browser.

That is the only way to increase your browser’s performance along with ensuring the safety of your sensitive data.Have you ever experienced similar problems while using Chrome extensions?

How many extensions have been currently installed in your browser? Which of them do you think is the real culprit behind any performance issues that you may have experienced?


Editor’s Note: This post was originally published in February 2019 and has been since revamped and updated in August 2020 for freshness, accuracy, and comprehensiveness.

Editor's Note: This article was originally published in February 2019 and was revamped and updated in September 2020 for freshness, accuracy, and comprehensiveness.