Apple introduced new photo compression technology in iOS 11 with the HEIC image format, a version of technology called HEIF (High Efficiency Image Format), that requires less storage space than the decades-old JPEG format.
The new photo compression technology means your photos take up half the space they used to, and enabling other enhancements like Apple's portrait mode.
While the HEIC format has compatibility problems, Apple implemented some safeguards to warn app developers to take precautions.
The problem stems from HEIC images conversion to JPEG, that is when a photo is cross-posted to Facebook or email, it can't be displayed on incompatible devices like Windows laptops, Android phones or Macs that don't run the latest macOS software.
As an internal format, HEIC images get converted into JPEG when it's time to post a photo outside the confines of iOS 11 or the latest macOS software.
Other way HEIC photos could leak out is with file-sync apps like Dropbox, Microsoft OneDrive and Google Drive, but luckily, those tools have have the compatibility issue covered.
Albeit, some free online tools like heictojpg.com can help you convert HEIC images into JPEG if you're stuck with one you can't handle. And if you want to convert HEIC photos on Windows or Mac PC, the free iMazing app can also help.
Apple Photos can also be configured to convert HEIC into JPEGs; simply tap on "Photos" in the iOS settings app, find the "Transfer to Mac or PC" section, then select "automatic" option.
The problem, however remains an issue with the general adoption of the HEIC and HEIF photo technologies, similar to Microsoft's JPEG XR and Google's WebP and may remain so until it's widely adopted by the tech companies.
