High Efficiency is a storage default, not a sharing format
iPhone, iPad, and Photos write HEIC because it saves gigabytes. Recipients on Windows see blank thumbs. Android messengers reject the attachment. Portals list PNG or JPG only. Toggling Camera to Most Compatible only helps pictures you take after lunch. Last summer’s trip is still HEIC. This spoke is that library problem: get the still onto the machine (or stay in Safari), decode locally, send PNG. PNG is lossless, so it is a better share than “Mail as JPEG” when you still plan to edit. It is also larger — if the friend only needed a chat preview, JPEG is enough. Local processing means IDs and family pics never become a cloud upload. For phone-only steps see the mobile spoke. For no-account framing see the free spoke. Hub is the general tool; this page is Apple-sharing friction only.