Contact
One address, read by one person. That person is Jim Liu, who builds and runs this site on his own; there is more about that on the about page.
hello@measureface.comCorrections are the most useful thing you can send
Several pages here correct numbers that the rest of this category repeats, which means this site is now making claims that could themselves be wrong. If you have read one of the papers cited and think a reading is mistaken, say so and point at the passage. A correction with a source attached will get the page changed, and the change will be visible rather than quiet.
The same goes for anything that looks like a measurement bug: a photo that produced an answer you know is wrong, a number that contradicts another number on the site, or a page that claims something it cannot support. Those are worth more than compliments.
Privacy and data requests
Write to the same address. The short version is that there is nothing held to request, because photos are measured in your browser and never sent anywhere, and the long version, including the biometric notice and what that means for a deletion request, is on the privacy and biometric notice page.
If you write about a privacy matter and the answer is genuinely "we hold nothing of yours", you will get that answer along with how to verify it for yourself in your own browser, rather than a form to fill in.
What to expect
It is one person in Sydney, so a reply may take a few days and there is no support queue behind the address. What will not happen is a request being ignored because it is inconvenient, and nothing sent here goes on a mailing list, because there is no mailing list.