Why your iPhone photos won't open on Windows
The file is not damaged and the transfer did not fail. Your phone simply saved the photo in a format the other machine has never been taught to read.
What HEIC actually is
Since iOS 11, iPhones have saved photos as HEIC rather than JPG. It is a genuinely better format: roughly half the file size at the same visible quality, with support for 16-bit colour and for storing several images in one file, which is how Live Photos and portrait-mode depth data work.
The problem is not the format. The problem is that Apple adopted it years before the rest of the world finished implementing it.
Where it breaks
- Windows, unless the HEIF Image Extensions have been installed from the Microsoft Store.
- Older Android phones, which will show the file but not open it.
- Web forms and upload fields that accept only JPG and PNG — job applications, insurance claims, marketplace listings.
- Plenty of desktop software, including older versions of Photoshop and most print-shop drop boxes.
The symptom is always the same and always unhelpful: the file is there, it has a sensible size, and nothing will display it.
Converting the photo you have
Converting to JPG solves it immediately and works everywhere. Expect the file to roughly double in size — that is the compression advantage of HEIC being given back — so if the result then hits an upload limit, compress it afterwards rather than converting at low quality.
One thing worth knowing: HEIC files carry the same location and device metadata as any other photo, and converting preserves it by default. If the photo is going to a stranger, strip that at the same time.
Stopping it happening again
On the iPhone, open Settings → Camera → Formats and choose Most Compatible. New photos are saved as JPG from then on; the ones already in your library stay as they are.
There is a second setting people miss. Settings → Photos → Transfer to Mac or PC → Automatic converts photos to JPG as they are copied off the phone. If that is set to Keep Originals, you get HEIC files on your computer even when everything else looks right.
Worth saying plainly: Most Compatible costs you about half your storage per photo. If your photos rarely leave your phone, leaving HEIC on and converting the occasional one is the better trade.