How to convert HEIC to JPG — and why iPhone photos won't open.

What HEIC actually is

Since iOS 11, iPhones have saved photos as HEIC — a still image stored inside a HEIF container, encoded with HEVC. Apple switched because it works: a HEIC photo is typically around half the size of the same shot as a JPEG at comparable quality, and it can hold things JPEG cannot, such as 10-bit colour, transparency, depth data and the multiple frames behind a Live Photo.

None of that is the problem. The problem is that HEVC is patent-encumbered, so decoding support was never as universal as JPEG's. The format is technically better and practically inconvenient — which is the whole story of HEIC in one line.

Why it won't open on the other end

Support is uneven rather than absent, and the gaps land in predictable places:

• Older Windows installs. Windows 11 and current Windows 10 builds generally preview HEIC in Photos and File Explorer, but a machine that hasn't been updated in a while — or one where the HEVC codec was never installed — shows a blank thumbnail or an error.
• Desktop apps that aren't the OS. Plenty of otherwise-current software still won't accept a HEIC import: older Photoshop and Office versions, most CMS and web upload forms, print-shop portals, insurance and government submission pages, and a lot of Android photo editors.
• Upload forms specifically. A form that only accepts .jpg, .jpeg and .png will reject a HEIC outright, no matter how modern the device viewing it is. This is where most people meet the problem.

JPEG, meanwhile, opens everywhere, on everything, and always has. When something needs to just work, that's the reason to convert.

Step by step

1. Open the converter. Go to HEIC to JPG.
2. Add your photos. Drag one HEIC file onto the dropzone, or select a whole batch — a holiday folder or an entire camera roll export is fine.
3. Press Convert to JPG.
4. Download. One photo comes back as a .jpg. A batch comes back as a single .zip containing every converted photo, keeping each original filename with the extension changed.

What changes, and what doesn't

• Resolution is unchanged. A 12-megapixel HEIC becomes a 12-megapixel JPEG. Nothing is resized.
• The file usually gets bigger. That's expected — JPEG is a less efficient codec, so the same picture takes more bytes. If size is the reason you're converting, run the results through Compress Image afterwards.
• JPEG has no transparency and no depth data. Portrait-mode depth information and Live Photo motion don't survive the conversion — the still frame does. Keep the originals if you might want to re-edit the blur later.
• Quality is re-encoded once, at a high setting. A single pass at high quality is visually indistinguishable from the original for viewing, sharing and printing. Repeatedly re-saving the same JPEG is what visibly degrades an image, and a one-time conversion isn't that.

Better still: stop your iPhone making HEIC

If you convert HEIC files often, fix it upstream instead. Two separate settings, and people usually only know the first:

• Shoot JPEG from now on. Settings → Camera → Formats → Most Compatible. New photos are saved as JPEG. You lose HEIC's space saving, and 10-bit HDR capture is limited in this mode — a reasonable trade if compatibility is a daily problem.
• Convert automatically when transferring. Settings → Photos → Transfer to Mac or PC → Automatic. Photos copied to a computer over a cable are converted to JPEG on the way out, while your library stays HEIC and keeps the space saving. This is usually the better setting of the two.

Sharing via Mail, Messages or most apps already converts to JPEG automatically. AirDrop and direct file access from a computer are the two paths that hand over the raw HEIC — which is exactly why AirDrop is how most people first run into this.