Convert HEIC to AVIF

No — that is the whole reason I built this. The conversion runs in your browser using WebAssembly, so your files never leave your device; there is no server in the loop at all. It also means the tool keeps working offline once the page has loaded, and there is no file size limit beyond your device’s memory.

Because HEIC and AVIF are similarly efficient, converting to JPG roughly doubles the file and WebP sits in between — AVIF is the only common target that keeps the size your iPhone achieved. Every current browser renders it, so for web publishing it is the no-compromise choice.

A little, once — that is unavoidable when re-encoding lossy sources, and I would rather say it than hide it. At the default quality the difference is not visible. What actually degrades photos is repeated round-trips; convert once from the camera-roll original and you are fine.

Browsers, image CDNs and modern CMSes all take AVIF happily. Upload forms, office software and older tools often reject it — the same compatibility wall HEIC hits. If a form refuses your file, HEIC to JPG is the universally accepted fallback.

Because they live in different neighborhoods: HEIC rules the Apple ecosystem, AVIF rules browsers. Chrome and Firefox will not render HEIC at all, so an iPhone photo cannot go on a website as-is. Converting moves the photo from phone-native to web-native at nearly the same size — versus HEIC to JPG, which roughly doubles the bytes for the same trip.

Before editing — cropping and color work should happen on the HEIC (or a lossless export) so the single lossy re-encode comes last, not first. And skip it for photos headed to forms, printers or family email threads: that world runs on JPG, and AVIF will bounce. This tool is specifically the camera-roll-to-website shortcut.