Melt guide

iPhone photos won't open on Windows? Convert to JPG on your Mac

Sent some iPhone photos to a Windows user and they can't open the HEIC files? Convert them to JPG on your Mac first.

4 min read

You sent a batch of holiday photos to your parents and they’re calling you saying nothing opens. Modern iPhones save as HEIC by default, and older Windows installs (or anything without the HEVC codec pack) just throw a “this file format isn’t supported” error. The fix is to convert them to JPG before you send.

Why this happens

HEIC is Apple’s preferred image format because it’s efficient. Windows 10 and 11 can technically open HEIC, but only if the user has installed the HEIF Image Extensions from the Microsoft Store — and a separate paid HEVC Video Extensions pack for some versions. Most people never do this, so HEIC files show up as unsupported.

The native way

Preview, one at a time. Open the HEIC, File → Export, choose JPEG, save. Repeat. Fine for two photos, painful for fifty.

Photos app drag-out. Hold Option while dragging a photo out of Photos and it exports as JPEG. Quick if your photos are already imported.

sips in Terminal. Batch convert a folder:

mkdir jpg
for f in *.heic *.HEIC; do
  sips -s format jpeg "$f" --out "jpg/${f%.*}.jpg"
done

That gives you a jpg/ folder full of compatible files.

The faster way

Drag the whole folder into Melt, set the output to JPEG, click Compress. It batch-converts everything and lets you also resize at the same time — useful if you’re emailing photos and don’t want a 40 MB attachment. Download Melt.

Converting a folder in Melt

  1. Open Melt.
  2. Drag your folder of HEIC files in.
  3. Set output format to JPEG.
  4. Set quality to 85 (good default for sharing).
  5. Optionally check resize to something like 2048px on the long edge.
  6. Click Compress.

A simpler permanent fix

Settings → Camera → Formats → Most Compatible on the iPhone makes every new photo a JPEG from the camera. You lose a bit of disk efficiency, but you stop running into this problem entirely. Worth considering if you regularly share with Windows users.

What you lose, what you keep

Converted JPEGs are roughly 1.5–2× the size of the originals at the same visual quality, and you drop from 16-bit to 8-bit colour. For sharing with family on Windows, none of that is noticeable. Keep the HEIC originals in your library; send JPEG copies.

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