results of a study on the impact on browser performance of thousands of the most popular Chrome add-ons. It is shown that some add-ons can have a rather strong impact on performance and create a large load on the system, as well as significantly increase memory consumption. During testing, the creation of a load on the CPU in active and background modes, memory consumption and the impact on the speed of displaying pages opened were evaluated. The results are presented in two samples covering the 100 and 1000 most popular add-ons.
Of the 100 most popular add-ons, Evernote Web Clipper (4 million users) and Grammarly (10 million users) add-ons are recognized as the most CPU-intensive add-ons, which lead to an additional 500 ms of CPU time when opening each page (for comparison, opening a test site without add-ons consumes 40 ms).
In general, 20 pads consume more than 100ms, and 80 take less than 100ms. Of the unexpected open was the relatively high resource consumption of the Ghostery add-on, eating up 120 ms of CPU time. The LastPass password manager ate 241ms, while Skype took 191ms. The specified resources do not stop rendering, but they block the beginning of interaction with the page and affect the power consumption of the device.
When sampling from 1000 additions, there are additions that create a significantly more tangible load:
In the page rendering delay test, Clever, Grammarly, Cash Back for Shoping, LastPass, and AVG slowed down the opening by 150-300ms, in some cases introducing delays comparable to the rendering of the page itself. In general, the situation is normal, since out of 100 additions, only 6 lead to a delay of more than 100 ms.
Results of a sample of 1000 additions:
When evaluating the load on the CPU created when the add-on performs background operations, the add-on showed itself
Avira Browser Safety, which took almost 3 seconds of CPU time, while the cost of other add-ons did not exceed 200 ms. Since the background is typically used to handle network requests made during page opening, the test was repeated on apple.com, which makes 50 requests instead of one. The results changed and Ghostery became the leader in creating the load, and Avira Browser Safety moved to 9th place (analysis showed that the load decreased due to the presence of the apple.com website in the white list).
Test results of 1000 additions:
20 worst scores when testing 1000 add-ons:
Since often the user writes off poor performance and resulting delays on the browser, and not on installed add-ons, Google experiments with informing about problematic additions. In the stable release of Chrome 83, the "chrome://flags/#extension-checkup" setting was introduced, which includes the output of informational messages about the possible impact of extensions on privacy and performance. When this option is enabled, the New Tab Page and Add-ons Manager starts to show a warning that add-ons may consume significant resources or access the user's personal data and activity.
A separate comparison was made between ad-blocking and privacy add-ons, in the context of saving resources by blocking external scripts and ad inserts. All add-ons provided a load reduction of at least three times when processing a test article from one of the news sites. DuckDuckGo Privacy Essentials took the lead, reducing test page load from 31 seconds to 1.6 seconds of CPU time by reducing network requests by 95% and download size by 80%. A close result was shown by uBlock Origin.
DuckDuckGo Privacy Essentials and uBlock Origin also came out on top in terms of resource consumption when running background operations.
When testing memory consumption, DuckDuckGo Privacy Essentials and uBlock Origin reduced memory consumption from 536 MB for a full test page to ~140 MB.
Similar testing was carried out for add-ons for web developers. CPU load:
CPU load during background operations
Draw delays:
Memory Consumption:
Source: opennet.ru