Essential storage keeps sign-in and learning features working. Google Analytics measures visits; Microsoft Clarity records interactions to help us improve usability. Both are optional and stay off until you choose. Read our privacy policy.
Measure recall with a focused quiz, then complete three practical challenges whose document structure is checked in your browser and rechecked on the server when saving to your account. Older browser-only passes must be retaken. These structural checks do not certify accessibility or authorship.