What is a HEIC file?
HEIC is the format iPhones and iPads have used for photos since iOS 11. Built on the HEVC video codec, it stores photos at roughly half the size of an equivalent JPG — but outside the Apple ecosystem support is patchy. Windows needs paid codecs, many websites reject HEIC uploads, and most printing services will not accept it.
In short, HEIC is Apple's iPhone photo format. It is best for staying on Apple devices — for everything else, convert it first. Its main limitations are poor support on Windows, Android, the web, and most upload forms; licensing restrictions keep adoption low.
Why convert HEIC to AVIF?
AVIF is built on the AV1 video codec and delivers the strongest compression of any mainstream image format — files are often about half the size of an equivalent JPG and noticeably smaller than WebP at the same visual quality. It supports transparency, HDR, and wide color gamuts.
Converting from HEIC to AVIF makes sense when you need performance-critical websites where every kilobyte counts, and modern image pipelines that can serve fallbacks. AVIF is supported by all current versions of Chrome, Firefox, Safari, and Edge.
Both formats support transparency, and this converter preserves the alpha channel — transparent areas in your HEIC stay transparent in the AVIF.
How to convert HEIC to AVIF
Drag and drop one or more HEIC files into the box above (or click to browse). Adjust the quality slider if you want smaller files or higher fidelity, then press Convert. Each file is decoded and re-encoded as AVIF on your own device in a second or two, and you can download results individually or grab everything as a ZIP.
Unlike most online converters, FileLark never uploads your files to a server. The conversion runs entirely inside your browser using modern web technology, which means it works offline once the page has loaded, there are no file size queues or daily upload limits, and your images can never be stored, scanned, or leaked — they simply never leave your device.