TL/DR: You won't be able to switch back to your old Gravatar image if you change your email (or have changed your email in the past). Please save and re-upload your Gravatar image if you want to keep it going forward.
Hi, everyone! I’m Felippe Rangel, a software engineer at Stack Overflow, and I’m here today to talk about a code change that will affect some users’ profile images.
One of the big projects we're working on right now is related to how we do Identity around the company. Over the past 12+ years since Stack Overflow's launch, there have been a lot of changes in the world of authentication and authorization, and although we have done our best to keep up with those changes, we're overdue for an upgrade. As we move towards a more centralized login solution for Stack Exchange, a lot of code cleanup is required, part of which includes having each Stack Exchange network account use one centralized Verified Email, instead of having individual email addresses associated with the user’s profile on each site on the Stack Exchange network.
But didn't you centralize email already, years ago? I can only see one email field in my settings...
Yes, voice inside my head, you are correct; from the user's perspective, this was done a while ago. That's why getting rid of the last traces of Email Per Site is being treated as a code cleanup, one that we've been working on for quite some time. And at this point in the road, it finally caught up with Profile Images, and therefore Gravatar.
Wait, where's my option to use a new Gravatar?
We haven't officially supported Gravatar in a while; we just made an effort to keep the existing ones working.
Why is this change even affecting Gravatar?
Stack Overflow uses a hashed version of your email address to access your Gravatar image. If your email address changes, we simply can no longer access that Gravatar URL. This wasn't a problem when your Per-Site Email was frozen in time. Now that your main email will actually affect that URL, your Gravatar profile image might be lost. We will keep displaying the image as long as you’re using it, but it will disappear from the image selector if you change your email.
But, but, I will really miss my Gravatar! How can I save it from doom?
We apologize for the inconvenience. To guarantee that you will keep the same image in your profile going forward, we humbly request that you download that image and re-upload it to your profile. It will be saved with our managed image provider (Imgur) and kept throughout this identity transition.
Thanks for understanding, folks! We hope it isn't too much of a bother to re-upload those images. We will do our best to keep displaying Gravatars from unchanged e-mail addresses, but we won't guarantee those forever (as we no longer officially support Gravatar).