> Photo & video compatibility
New HEIF and HEVC still image and video formats in iOS 11 take up less storage space on your device. They roughly double the amount you’re able to store. Capturing media using them requires an iPhone 7 or 7 Plus or later, a 10.5-inch iPad Pro, or a secondgeneration 12.9-inch iPad Pro, which have A10/M10 or A11 Fusion/M11 chips that enable hardware encoding.
Choose the format that’s used in Settings > Camera > Formats. Pick High Efficiency for the new formats; Most Compatible is good to ensure files work with other apps and workflows relying on older formats — particularly useful if you use a Mac app that doesn’t work with HEIF/HEVC. When you share HEIF/ HEVC content to a destination whose support for it is unclear, iOS 11 will autoconvert it to a more compatible format, which imposes a slight delay — a progress indicator is shown.
Older iOS devices can view, edit and duplicate HEIF and HEVC files, but their hardware limits the resolution and frame rate of video they can work with. If the hardware in your device supports HEIF/ HEVC encoding, set them as the default to save space, or opt for older formats for broader compatibility.