On iPhone, Settings > Camera > Formats offers two choices: High Efficiency captures photos as HEIF and video as HEVC, while Most Compatible captures photos as JPEG and video as H.264. That one toggle decides how every new file coming out of the Camera app is encoded.
The genuinely confusing part is not the toggle. It is that the words "Most Compatible" appear twice in iOS — once in Camera settings, once in the Share sheet — and Apple's own documentation gives them different outcomes. That second one is where most articles on this topic go wrong, so it gets its own section below.
The two settings, at a glance
| Setting | Photos | Video | Apple's wording |
|---|---|---|---|
| High Efficiency | HEIF | HEVC (also known as H.265) | "the space-saving HEIF and HEVC formats" |
| Most Compatible | JPEG | H.264 | "capture photos and videos in JPEG and H.264 formats" |
Apple spells the acronyms out on its HEIF and HEVC support page: "HEIF (High Efficiency Image File Format) for photos" and "HEVC (High Efficiency Video Coding), also known as H.265, for videos."
The switch itself is described just as plainly: "Tap Formats, then tap Most Compatible," after which "All new photos and videos will now use JPEG or H.264 format. To return to using the space-saving HEIF and HEVC formats, choose High Efficiency." Apple's Windows transfer article says the same thing from the other side: "Tap Most Compatible. From now on, your camera will capture photos and videos in JPEG and H.264 formats."
Two conditions travel with that, both worth quoting exactly:
- "This setting is available only on iPhone and iPad devices that can capture media in HEIF or HEVC format." If the option is missing on your device, that is the stated reason.
- The models Apple lists as able to capture those formats begin at "iPhone 7 or iPhone 7 Plus or later."
The setting governs new captures only. Nothing already sitting in your library gets re-encoded when you flip it.
What High Efficiency actually buys you
One sentence carries Apple's entire case: "HEIF and HEVC offer better compression than JPEG and H.264, so they use less storage space on your devices and iCloud Photos, while preserving the same visual quality."
Read that as a claim about storage, and note that the page attaches no percentage to it. Apple's recommendation is nonetheless explicit — "Though capturing in HEIF and HEVC format is recommended, you can set iPhone or iPad to capture media using the older formats, which are more broadly compatible with other devices and operating systems."
Take "more broadly compatible" literally. It is a comparison between two formats, not a promise that every device on earth plays H.264.
The tech-spec pages line up with the toggle. iPhone 17 Pro lists "Video formats recorded: HEVC, H.264, ProRes, and ProRes RAW"; iPhone 17 lists "Video formats recorded: HEVC and H.264." On the photo side it is "Image formats captured: HEIF, JPEG, and DNG" for the Pro and "HEIF and JPEG" for the non-Pro.
The trap: there are two "Most Compatible" controls
Here is the Share sheet wording, verbatim from Apple's Share photos and videos on iPhone page: "Adjust the file format: Tap Automatic for the best file format for the destination, tap Current to prevent a file format conversion, or tap Most Compatible and files may convert to JPEG or MOV."
Put the two side by side:
| Where you find it | What Apple says it does |
|---|---|
Settings > Camera > Formats → Most Compatible | "capture photos and videos in JPEG and H.264 formats" |
| Share sheet → Options → Most Compatible | "files may convert to JPEG or MOV" |
Three differences that matter:
- Scope. The camera setting decides how footage is recorded. The Share sheet option decides what leaves your phone on this one share — it changes nothing about future recordings.
- Wording. One says H.264, a codec. The other says MOV, a container. They are not the same kind of thing, and Apple's specification pages describe what iPhone records only in codec terms ("HEVC, H.264"), not file extensions.
- Certainty. The Share sheet sentence says files "may convert," not "will convert."
The genuinely useful neighbour in that same sentence is Current, which Apple describes as being there "to prevent a file format conversion." If you want the file to leave exactly as it sits in your library, that is the documented switch.
What to do when a file still will not open
Apple gives three different answers for three different routes out of the phone, and all three hinge on the word might:
| Route | Apple's wording |
|---|---|
| iCloud Photos | "the media is preserved in its original format, resolution, and frame rate" |
| AirDrop, Messages, email | "the media might automatically be shared in a more compatible format, such as JPEG or H.264" — and only if "the receiving device doesn't support the newer media formats" |
| USB import to Photos, Image Capture, or a PC | "the media might be converted to JPEG or H.264" |
That third row has an opt-out. Apple: "If you don't want it to be converted, open Settings, tap Apps, tap Photos, then scroll down and tap Keep Originals."
For files already on a Mac, Apple documents a manual conversion: open the HEVC video in QuickTime Player, choose File then Export As, and "use the pop-up menu to change from Smaller File Size (HEVC) to Greater Compatibility (H.264) before you click Save." Those two phrases are the literal button labels, so they are easy to find on screen.
If you are not on a Mac, or you just want the file re-wrapped and re-encoded without installing anything, do it in the browser:
Try it right here
Runs in your browser. Your file is not uploaded anywhere.
It runs locally in your tab — the video is read from disk, converted, and handed back, never uploaded. The same job as a standalone page is at MOV to MP4, and if the problem is size rather than codec, compress video is the one you want. The rest are listed under all Clapr tools.
Gotchas worth knowing
Old devices are not a simple codec question. Apple: "On some older devices, support for HEVC is affected by the resolution and frame rate (fps) of the video. Resolutions of 1080p or lower and frame rates of 60 fps or lower are more broadly compatible with older devices." So a 4K 60 fps HEVC clip and a 1080p 30 fps HEVC clip can behave differently on the same machine.
Windows. Apple's route is to "Install the Apple Devices app from the Microsoft Store," and it adds that with iCloud Photos on, "you must download the original, full resolution versions of your photos to your iPhone or iPad before you import to your PC." If HEVC playback is the sticking point on the receiving end, why HEVC/H.265 will not play in Google Drive covers the same collision elsewhere.
ProRes sits above both options. Apple: "If you turn ProRes off in the Camera app, the video format defaults to either High Efficiency Video Coding (HEVC) or Most Compatible (H.264)." So the Formats toggle is what ProRes falls back to, not an alternative to it.
FAQ
Is High Efficiency or Most Compatible better? Apple states that "capturing in HEIF and HEVC format is recommended," and that the older formats are "more broadly compatible with other devices and operating systems." So: stay on High Efficiency unless you regularly hand files to devices or software that choke on HEVC, in which case Most Compatible removes that step.
Does Most Compatible convert my existing photos and videos? No. Apple's wording is that "All new photos and videos will now use JPEG or H.264 format." Existing files stay as they are.
Why can't I find Most Compatible on my iPhone? Apple: "This setting is available only on iPhone and iPad devices that can capture media in HEIF or HEVC format." The models it lists as capable start at "iPhone 7 or iPhone 7 Plus or later."
Does switching to Most Compatible disable any recording modes? Apple's official documentation doesn't state this — check the official documentation for your model before assuming either way.
Why did my video arrive as H.264 when my phone is set to High Efficiency? Most likely the sharing route converted it. Apple says that over AirDrop, Messages, or email the file "might automatically be shared in a more compatible format, such as JPEG or H.264" when "the receiving device doesn't support the newer media formats." Tapping Current in the Share sheet is Apple's documented way "to prevent a file format conversion." More format-limit write-ups live in the limits hub, and the Gmail MOV attachment problem is a close cousin of this one.
Wording quoted from Apple's Using HEIF or HEVC media on Apple devices, Transfer photos and videos from your iPhone or iPad to your Mac or PC, About Apple ProRes on iPhone, and the iOS 27 Share photos and videos on iPhone guide page, checked 17 September 2026. Apple revises these pages — verify against the official documentation before relying on them.
