HEIC not supported by an app — convert it on your Mac

You drag a HEIC into your design tool, your CMS upload form, or some specialist piece of software, and it bounces with “unsupported format”. macOS itself understands HEIC fine — but the app you’re trying to feed doesn’t, and there’s no setting in there to make it.

Why this happens

HEIC is relatively new (Apple adopted it in 2017) and uses HEVC compression that requires a licensed decoder. Many cross-platform apps, older Mac apps, and most web upload forms still expect JPEG or PNG. Even apps that recently added HEIC sometimes only support reading, not writing — or only on the newest macOS.

The native way

Preview’s Export. Open the HEIC, File → Export, pick JPEG or PNG, save. The simplest path for a one-off:

• Use JPEG for photos (smaller files, lossy).
• Use PNG for screenshots or anything with sharp edges or text (lossless, larger).

sips in Terminal. Slightly faster, scriptable:

sips -s format jpeg photo.heic --out photo.jpg
sips -s format png photo.heic --out photo.png

Photos app drag. Drag a photo out while holding Option to get a JPEG, or hold both Option and Shift for the source-format export.

The faster way

Drag the HEIC into Melt, pick the target format (JPEG or PNG), set quality if it’s JPEG, click Compress. Useful when you have several files to feed to the same picky app. Download Melt.

Quick conversion in Melt

1. Open Melt.
2. Drag the HEIC in.
3. Choose JPEG (for photos) or PNG (for graphics/screenshots).
4. Pick quality if JPEG.
5. Click Compress.

Which format does the app actually want?

Most upload forms and design tools accept both JPEG and PNG. If you’re unsure:

• Photo-heavy content (people, landscapes, anything with smooth gradients) → JPEG.
• Screenshots, logos, diagrams, anything with sharp edges or transparency → PNG.

For web work specifically, WebP and AVIF are smaller still, but only if you control the destination — many apps still don’t accept them.

What you lose, what you keep

JPEG conversions are lossy and roughly double the file size at matched quality compared to HEIC. PNGs are lossless but often 3–5× larger than the HEIC for a photo. Both lose any depth/portrait/live-photo metadata. For one-off “the app needs JPEG” conversions, none of that matters. For archival, keep the HEIC.