zulip/templates/zerver/help/change-your-avatar.md

Change your avatar

By default, Zulip uses avatars from Gravatar. If your email address already has a gravatar associated with it, Zulip will use your existing gravatar.

You can also upload a custom avatar to Zulip.

{settings_tab|your-account}

2. Under User Avatar, click Upload new avatar and choose an image to upload.