Convert HEIC to AVIF — Free, Fast & Private
HEIC and AVIF are cousins. Both wrap still images in the same ISO base media container that MP4 uses, and both borrow their compression from a video codec. The difference is which codec, and that difference decides everything about where the file will open.
HEIC uses HEVC (H.265), which is encumbered by a thicket of patent licensing. That is why no major browser will display a HEIC file, and why Windows asks you to buy a codec extension. AVIF uses AV1, which the Alliance for Open Media released royalty-free — and that single fact is why every major browser renders AVIF natively while none of them touch HEIC.
So the conversion is not really about compression. Both formats compress a photograph to a broadly similar size. It is about turning a file that only Apple’s ecosystem opens comfortably into one the open web accepts.
The one conversion that keeps your colour depth
This is the reason to choose AVIF over WebP or JPEG for an iPhone photo. HEIC commonly stores 10-bit colour. JPEG is 8-bit. WebP is 8-bit. AVIF handles 10- and 12-bit natively.
In practice that shows up in wide, smooth gradients — a clear sky, a sunset, a studio backdrop — where 8 bits gives you 256 steps per channel and the transitions can break into visible bands. Keeping 10 bits gives you 1,024 steps and the gradient stays smooth. On a busy, detailed photograph you will never notice the difference; on a gradient you sometimes will.
What is not preserved: the depth map behind Portrait mode, the HDR gain map, and the video track of a Live Photo. A HEIC is a container that can hold all of these, and conversion extracts the main image alone. Keep your originals.
AVIF has to be available in your browser
Encoding happens on your device, so AVIF output depends on your browser having a working AVIF encoder. MiniPx probes for one and only shows AVIF in the format list when it is genuinely usable. It also verifies the result: some browsers report success and silently hand back a PNG, so MiniPx checks the file’s magic bytes and refuses the file rather than giving you a multi-megabyte PNG wearing an .avif extension.
If AVIF is not offered, HEIC to WebP is the next best thing for web use — smaller than JPEG, universally supported, at the cost of dropping to 8-bit.
Privacy and orientation
Re-encoding through a canvas leaves the EXIF behind, so the GPS coordinates, capture time and device model in your iPhone photo do not travel into the AVIF. The orientation flag is applied to the pixels first, so photographs taken sideways stay upright instead of flipping when the metadata is dropped.
Nothing is uploaded — the conversion runs in your browser, which is the point when the input is your camera roll. For anything leaving the web, HEIC to JPG remains the safe choice, since email, print services and government forms overwhelmingly expect JPEG.
AVIF can carry deep colour where most formats stop at 8 bits per channel — when a conversion costs you colour depth sets out what each depth can represent.