Your browser does the work
When you open a test, your browser downloads the page and a small program for that test. From then on, everything happens on your device. There is no server measuring your microphone or watching your camera.
Microphone and camera access
Browsers protect your microphone and camera. A site can only use them after you allow it, and only on a secure (https) connection. Kensa Lab asks only when you press a button such as Allow microphone, and only on tests that need it.
- The sound or picture is passed straight from your device to the test running in your browser tab.
- When you stop the test or leave the page, access is released. Most browsers show an icon while a site is using your microphone or camera.
- You can withdraw permission at any time in your browser settings.
How results are calculated
- Sound level is measured as the root mean square of the audio samples and shown in dBFS, where 0 dB is the loudest a digital signal can be.
- Pitch is found with the McLeod pitch method, then converted to a note name and cents using equal temperament with A4 at 440 Hz by default.
- Webcam resolution and frame rate come from the video track your browser actually delivers, not the camera’s advertised specification.
- Clicks per second is the number of clicks divided by the seconds in the test.
- Words per minute counts every five correctly typed characters as one word.
- Reaction time is the time between the colour change and your click, tap or key press. It includes small delays from your screen and input device.
These calculations are written in code and tested automatically, so the explanation on each page always matches what the test does.
What we measure about the site
We count page views with cookie-free Cloudflare Web Analytics and receive small anonymous events, such as “test started” or “camera not found”, so we can find and fix problems. These events never include audio, video, your results or anything you typed. Details are in our privacy policy.