Make a profile picture

No. A face detector and a cut-out model run inside your browser tab, and the picture is drawn there. Your face does not go to a server, which is more than most avatar and headshot apps can say.

Around your face: the face fills about 40% of the width with the eyes a little above the middle, the usual headshot framing that still looks right when a site crops it to a circle. If no face is found, for a pet or an object, the whole subject is fitted in instead.

Yes, as a photo file. Check your framing and light first with the webcam test, save a snapshot as JPG, then drop it here.

A colour that contrasts with your hair and clothes and stays recognisable at thumbnail size. Soft, light colours read as professional on LinkedIn; bright ones stand out in Slack and Discord member lists. Using the same colour everywhere makes you easier to spot.

It is larger than any site displays, so every site can scale it down sharply: LinkedIn shows 400 × 400, Slack and Discord show much smaller. Uploading a bigger square than needed avoids the blur you get when a site enlarges a small one.

Most sites crop to a circle themselves, so a square with a colour background works everywhere. Choose Circle when the picture will be shown as-is on a page, in a slide or an email signature, where a square would look boxy; the corners are transparent, so it is saved as PNG.

Fine, flyaway hair against a busy background is the hardest case for the cut-out. A photo against a plain wall works best. You can also run the photo through the background remover first, adjusting Keep around the edges, and drop the PNG it gives you here.