Question 1

What is a HEIC file and why can't I open it?

Accepted Answer

HEIC is the High Efficiency Image Container format that Apple devices use by default since iOS 11. It stores the same photo in roughly half the size of a JPEG, but Windows, many Android apps and a lot of websites still do not support it, so the file looks unopenable outside the Apple ecosystem.

Question 2

Does converting HEIC to JPG lose quality?

Accepted Answer

A small amount, because both formats are lossy. At quality 85–90 the difference is invisible in normal viewing, while the file becomes universally readable. If you want to keep every pixel intact, convert to PNG instead — the file will be much larger but lossless.

Question 3

Can I convert many HEIC photos at once?

Accepted Answer

Yes. Drop a whole folder of photos in and they are queued and converted three at a time, then you can save them individually or all at once. There is no limit on how many photos you convert.

Question 4

Are my photos uploaded anywhere?

Accepted Answer

No. The HEIC decoder runs as WebAssembly inside your browser, so your photos are decoded on your own device and never sent to a server. This matters for holiday photos, screenshots of documents and anything else personal.