High Efficiency vs Most Compatible: keep HEIC and still get JPGs
What each iPhone camera setting changes, Apple’s advice for Windows, one real iPhone photo measured, and three ways to send JPGs.
Keep High Efficiency unless your photos go to a Windows PC by cable every week. High Efficiency saves new photos as HEIC and new videos as HEVC. Most Compatible saves JPEG and H.264 instead. JPEG and H.264 need up to 2 times the space for the same look, by Apple’s 2017 launch figure. Apple recommends High Efficiency, and for Windows PCs it now advises Most Compatible. You also do not have to pick one format for everything. You can keep HEIC on the phone and still hand out JPGs, through the share sheet, the transfer setting or iCloud.com. I checked every path below against Apple’s current support notes and iOS 27 guides, and I measured one real iPhone photo.
This story was written with the assistance of an AI writing program. Every figure comes from a file measured with Blinkimg’s engine or from the source linked beside it.
What do High Efficiency and Most Compatible actually change?
The Formats switch sets the file type of every new photo and video. It sits in Settings > Camera > Formats. Apple’s support note on HEIF and HEVC media says every iPhone from the iPhone 7 on can capture HEIF.
- High Efficiency saves photos as HEIF, in files that end in .heic, and videos as HEVC, also called H.265.
- Most Compatible saves photos as JPEG and videos as H.264. In Apple’s words: “All new photos and videos will now use JPEG or H.264 format.”
Two words in that sentence matter. “New” means the photos you already took keep their format. “Videos” means the switch changes your videos as well.
High Efficiency is the default. Apple’s Photos guide for the Mac calls HEIC “the default image format for Apple devices”. The support note says capturing in HEIF and HEVC “is recommended”. The reason is space: the two formats “use less storage space on your devices and iCloud Photos, while preserving the same visual quality”.
The catch is where the files open:
- A HEIC opens on iPhones, iPads and Macs, and on Android 8.0 and later, according to Android’s developer documentation. Among web browsers, only Safari 17 and later shows one, according to caniuse. Google’s list of files a Chromebook opens has no HEIC, and Windows needs two Microsoft Store extensions.
- A JPEG opens on every phone, computer and browser.
I build Blinkimg, an image compressor and converter. My guide to what a HEIC file is and how to open one covers each device, and what a HEIC holds inside.
Is Most Compatible better quality?
No. Most Compatible buys compatibility, not quality. Both settings save a processed, compressed file. Apple’s developer guide to RAW capture sets RAW apart from the usual camera output, which comes “in a compressed format for efficient storage and display”. That covers the HEIC and the JPEG alike.
Three claims about quality keep coming back in forum threads and older blog posts:
- “Most Compatible does not compress the photo.” It does. JPEG is a lossy format, so every JPEG the camera saves is compressed.
- “HEIF is lossless.” Not the HEIC your iPhone saves. I measured a real iPhone 12 Pro photo, 2268 × 4032 pixels, that the phone saved as a 1,956 KB HEIC. The same pixels kept losslessly, as a PNG, take 11,731.3 KB: 6.0 times the HEIC.
- “iPhone photos are 10-bit, so JPEG throws colour away.” The iPhone 12 Pro photo I measured is 8 bits per channel, in the Display P3 colour space. HEIF can hold more bits; this photo does not use them.
For more room to edit exposure and colour, Most Compatible is the wrong switch. Apple’s route for that is ProRAW, covered below.
How much space does High Efficiency save?
The published figures put a HEIC at about half the size of a JPEG of the same quality. None of them is mine:
- Apple’s 2017 announcement of the iPhone 8 promised “up to two times compression and storage for twice the photos and videos” from HEIF and HEVC.
- WebKit’s notes for Safari 17.0, in 2023, put a HEIC at “about half the space of an equivalent-quality JPEG file”.
- In a lab test on the HEIF reference site, JPEG needed 2.39 times the file size of HEVC on average, for the same measured quality.
A fair camera test needs one scene shot in each setting, and I have not run that pair. What I did measure is the copy you send. I ran the same iPhone 12 Pro HEIC through Blinkimg’s engine:
- JPG at Auto quality: 940.7 KB, 51.9% smaller than the HEIC.
- WebP at Auto: 748.5 KB, 61.7% smaller.
- AVIF at Auto: 474.5 KB, 75.7% smaller.
A JPG smaller than the HEIC looks like a contradiction of Apple. It is not one. Apple compares the formats at the same quality. The phone saves its HEIC at a high quality, with an HDR gain map and an Exif block inside. Blinkimg’s Auto setting picks the quality a screen needs. The engine then writes an 8-bit sRGB JPG with no gain map and no Exif block.
Ask for more quality and the JPG grows. Our small 800 × 600 photo-like test HEIC weighs 199.7 KB. As a JPG it came out at 71.9 KB at Auto, 102.8 KB at quality 85 and 139.3 KB at quality 90.
So keep HEIC for the photos you store, and make JPG copies for the photos you send.
What else changes when you switch?
Video
The H.264 videos that Most Compatible records need more space than HEVC for the same look. Some older guides add that certain video modes need High Efficiency, but Apple’s current iOS 27 guides list no such limit. After you switch, check the modes you use in Settings > Camera > Record Video.
48-megapixel photos
On an iPhone that shoots 48 MP, the format choice also sets the resolution. Apple’s support note on HEIF Max and ProRAW says standard HEIF gives photos of up to 24 MP, and HEIF Max or RAW Max up to 48 MP. The note is written in HEIF and RAW terms. After you switch to Most Compatible, look at the Formats screen to see which resolutions it offers.
ProRAW
ProRAW is the setting for heavy editing, and it makes a different kind of file: a DNG, whichever everyday format you pick. Apple says ProRAW files are “10 to 12 times larger than HEIF or JPEG files”, about 25 MB at 12 MP and 75 MB at 48 MP. Apple offers ProRAW on its Pro models, and ProRAW does not work with Live Photos or in Portrait mode.
Can you keep HEIC and still send JPGs?
Yes. The camera setting is one of three switches. The other two, in the share sheet and in the transfer setting, decide what leaves the phone.
From the share sheet, one share at a time
In Photos, select the photos, tap Share, then tap Options. You get three choices: Automatic, Current and Most Compatible. Apple’s iPhone guide to sharing photos says to “tap Current to prevent a file format conversion”. With Most Compatible, the guide says, “files may convert to JPEG or MOV”.
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Sharing a photo also “includes sharing its associated metadata”, in the guide’s words, and that can include where you took it.
When the other device cannot read HEIC
AirDrop, Messages and email can convert on their own. Apple’s support note says they convert when “the receiving device doesn’t support the newer media formats”. Even then, the file only might convert, so treat it as a bonus, not a plan.
From iCloud.com
With iCloud Photos on, the original HEIC stays in iCloud. Apple says each file is “preserved in its original format, resolution, and frame rate”. A photo downloaded from iCloud.com comes “in the most compatible format for the device”, according to Apple’s iCloud guide.
Automatic or Keep Originals: which Transfer to Mac or PC setting?
Choose Keep Originals when the computer reads HEIC, and Automatic when it does not. Open Settings > Apps > Photos and scroll down to Transfer to Mac or PC.
- Keep Originals copies the exact files the phone saved, HEIC and HEVC included. A Mac opens them as they are.
- Automatic lets the phone convert on the way. Apple’s wording is careful: the media “might be converted to JPEG or H.264”.
That “might” shows on Windows 11. Two threads from 2025 describe the gap:
- On Apple’s community forum in February 2025, an iPhone 13 owner set Automatic. A Windows 10 PC received JPGs, and a Windows 11 PC received HEIC files. The thread has no solution.
- On Microsoft’s Q&A site in August 2025, HEIC and MOV files reached a Windows 11 PC after a device reset, with Automatic set. A moderator said the iPhone skips the conversion when the PC reports that it can read HEIC or HEVC. Removing the iPhone in Device Manager and reconnecting it brought JPEG photos back, but the videos stayed MOV.
Those are user reports, not Apple’s documentation. Apple’s note on transferring photos to a Windows PC, dated 14 September 2026, gives a shorter answer. It says to install the Apple Devices app from the Microsoft Store, and to pick Most Compatible for “best compatibility with Windows”. With iCloud Photos on, the note adds that “you must download the original, full resolution versions” before you import.
The other route is to make Windows read HEIC. The HEIF Image Extension is free, but its listing says the HEVC Video Extensions package “must be installed” as well. HEVC Video Extensions costs $0.99 in the US Microsoft Store.
What about the photos you already took?
They stay HEIC, because the switch only changes new photos. Keep those HEIC files as your originals, and convert copies when someone needs a JPG:
- On a Mac: in Photos or Preview, choose File > Export and pick JPEG. In Photos, JPEG sits in the Photo Kind menu, per Apple’s Photos guide. In the Finder on macOS 27, select the files and use Quick Actions, then More, then Convert Image.
- On Windows: the Photos app needs the two extensions above before it opens a HEIC at all.
- On any device, a phone included: a browser HEIC to JPG converter converts a batch. The one I build takes 10 photos a run on the free plan.
So which should you choose?
Choose by where your photos go, not by which format is newer.
- Only Apple devices and iCloud: High Efficiency, with Transfer to Mac or PC set to Keep Originals.
- A Windows PC, by cable, every week: Most Compatible, as Apple advises. If you keep High Efficiency instead, check that your first import arrives as JPG.
- Friends on Android, a Chromebook or Windows: High Efficiency, and share their photos through Share > Options > Most Compatible.
- School, job or visa portals: High Efficiency, and convert a copy of each photo you upload. If a portal wants every photo in one file, a HEIC to PDF converter puts each photo on a JPEG page of one PDF. Our iPhone 12 Pro photo became a 941.7 KB one-page PDF.
- Heavy editing on a Pro model: ProRAW, not Most Compatible.
- A phone that is nearly full: High Efficiency, for the space it saves.
Questions people ask
Should I use High Efficiency or Most Compatible on my iPhone?
Use High Efficiency unless your photos go to a Windows PC by cable every week. Apple recommends High Efficiency because HEIC and HEVC take less space for the same look. For Windows PCs, Apple advises Most Compatible. Otherwise, keep HEIC and send JPG copies through Share > Options > Most Compatible.
Which is better quality, High Efficiency or Most Compatible?
Neither setting adds quality. Both save a processed, compressed photo, and Apple says HEIF and HEVC keep the same visual quality in less storage. Most Compatible only changes the file format to JPEG and H.264. For more room to edit exposure and colour, Apple’s route is ProRAW on a Pro model.
Does Most Compatible take more storage?
Yes. Apple says HEIF and HEVC use less storage than JPEG and H.264 at the same visual quality. Apple’s 2017 launch figure was up to 2 times the compression, and WebKit’s engineers put a HEIC at about half the space of an equivalent-quality JPEG. Every new photo and video grows under Most Compatible.
Does switching to Most Compatible convert my old photos?
No. Apple says the switch applies to new photos and videos, so everything already in your library keeps its format. For JPGs of older photos, export copies: Photos and Preview on a Mac export JPEG, and a browser converter handles batches on any device. Keep the HEIC files as your originals.
Why do my iPhone photos still reach Windows 11 as HEIC?
With Transfer to Mac or PC set to Automatic, Apple only says photos might be converted. Windows 11 users reported HEIC arriving anyway in 2025. A Microsoft Q&A moderator said the iPhone skips the conversion when the PC reports HEIC support. For Windows, Apple advises Settings > Camera > Formats > Most Compatible.
Should I choose Automatic or Keep Originals?
Choose Keep Originals if your computer is a Mac, or a PC with the HEIF and HEVC extensions. You get the exact files the phone saved. Choose Automatic if the PC cannot open HEIC, so the phone can convert on the way. The setting sits in Settings > Apps > Photos, under Transfer to Mac or PC.
Can I send a JPG without changing my camera setting?
Yes. In Photos, select the photo, tap Share, then Options, and choose Most Compatible. Apple’s iPhone guide says the files may then convert to JPEG or MOV. Current sends them unconverted. AirDrop, Messages and email may also convert on their own, but only when the receiving device cannot read HEIF.
Should I choose HEIF or RAW?
HEIF for everyday photos; ProRAW for heavy edits to exposure and colour. Apple says ProRAW files are 10 to 12 times larger than HEIF or JPEG files: about 25 MB at 12 MP and 75 MB at 48 MP. Apple offers ProRAW on Pro models, and ProRAW does not work in Portrait mode or with Live Photos.
What to set on your iPhone today
Leave Settings > Camera > Formats on High Efficiency, unless a Windows PC gets your photos by cable every week. Then open Settings > Apps > Photos and set Transfer to Mac or PC for your computer. Pick Keep Originals for a Mac, and Automatic for a PC that cannot open HEIC. The next time someone asks for a JPG, send it through Share > Options > Most Compatible.
For the HEIC photos already in your library, Blinkimg converts them to JPG from any browser for free, with no signup. Blinkimg strips location data by default and deletes every file within 24 hours. If you convert whole albums every week, Blinkimg Pro Max costs $8.50 a month. Pro Max adds unlimited conversions, files up to 1 GB and the fastest queue.
