A question we get asked all the time: Will Clarity slow down my site and affect website performance?
Since we are talking about speed the quickest answer is No.
The Clarity team takes website performance seriously; in fact, vs our competitors, we have the least effect on a webpage load time. This is because Clarity’s code is asynchronous and therefore designed to have a very low impact on page load time.
Asynchronous vs synchronous code
Synchronous code – This is where tasks are performed one at a time and you need to wait for a task to finish before the next one can begin.
Asynchronous code – This is where tasks can begin before the previous one finishes. This enables multiple requests concurrently meaning more tasks can be completed in a much shorter period.
Clarity speed tests
To demonstrate Clarity’s impact we ran tests on five different websites which had Clarity installed.
- Time of day: 13:00 (Coordinated Universal Time)
- Internet connection: WIFI
- Browser: Playwright
|Website||Location||Daily sessions||Total blocking time (ms)||Long tasks||Download script size (bytes)|
|Music sharing||South Korea||0.1m||0||2||25962|
|Car rental||Czech Republic||0.1m||0||1||25218|
Total Blocking time: The time in which the main site thread is blocked to do other tasks like downloading the script. As seen above, Clarity almost never blocks your site.
Long Tasks: Tasks producing blocking time. As seen above, Clarity results in zero or one long task which is the script downloading task (tag request).
Downloaded script size: This measures the script size and the size of processing requests. In clarity, the number decreases to ~300 after the script is downloaded for the first time in a day and stays the same for the entire day (the script gets cached in the browser for 1 day and needs to be downloaded again after that.)