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Supports: AVIF
These two look almost identical from the outside: both are still images wrapped in an ISO base media container, both descend from video codecs, both compress photographs to roughly half of what JPEG needs. The difference that matters is what is inside. AVIF carries an AV1-coded picture and is a web format; HEIF as written here carries an HEVC-coded picture and is an operating-system and photo-library format. Short answer: stay on AVIF if the file is going on a web page or to a mixed audience, and convert to HEIF when an Apple-ecosystem app, a photo library or a device pipeline expects the HEVC payload.
| Property | AVIF | HEIF (as produced here) |
|---|---|---|
| Full name | AV1 Image File Format | High Efficiency Image File Format |
| Specification | AOMedia, v1.2.0 (16 October 2025) | ISO/IEC 23008-12 (MPEG-H Part 12) |
| Base container | ISO/IEC 14496-12 | ISO/IEC 14496-12 |
| Payload codec | AV1 | HEVC / H.265 |
| Licensing of the codec | Royalty-free, Alliance for Open Media | Patent-encumbered; HEVC pools charge licensees |
| Colour depth in the spec | 8, 10 or 12-bit, plus HDR and wide gamut | 8, 10 or 12-bit depending on HEVC profile |
| Transparency | Yes, as an auxiliary alpha image item | Yes, as an auxiliary alpha image item |
| Animation | Yes, AV1 image sequences | Yes, HEVC image sequences |
| Browser support | ~94.7%: Chrome 85+, Firefox 93+, Safari 16.4+, Edge 121+ | Not a web image format; Chrome, Edge and Firefox do not decode it |
| Natural home | Web delivery, cross-platform sharing | Apple Photos, iOS/macOS apps, device camera pipelines |
.avif but accepts .heif / .heic.| Property | Result |
|---|---|
| Pixel data | Decoded from AV1 and re-encoded as HEVC — a second lossy pass |
| Transparency | Preserved; there is no background-fill step on this conversion |
| Animation | An animated AVIF is reduced to its first frame on a still target |
| Resolution | Kept, unless you change it under Image resolution |
| Compression efficiency | Broadly comparable; AV1 usually edges HEVC at low bitrates |
| File extension | .heif — see the FAQ below on when to use .heic instead |
.avif files onto the page or click "Add Files". Queue as many as you like; they all convert with the same settings..heif. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours — no sign-up, no watermark.Because the container is the only thing they share. Both are ISO base media files, but the picture inside an AVIF is coded with AV1 and the picture inside a HEIF is coded with HEVC — different codecs entirely. Renaming the file does nothing; the pixels have to be decoded from AV1 and re-encoded as HEVC, which is what happens on our servers.
Some, in principle. Both formats are lossy by default, so this is a lossy-to-lossy transcode and the second encode adds a generation of loss on top of whatever the AVIF already discarded. Keeping the Quality Preset at Very High makes it hard to spot at normal viewing sizes, but nothing can restore detail the original AVIF encode already threw away.
.heif file actually use?HEVC. Our encoder picks the payload from the output extension — an .avif target gets AV1, and anything else in the HEIF family, including .heif and .heic, gets HEVC. That is exactly the behaviour Apple's tools and most HEIF readers expect, and it is why this conversion is a real transcode rather than a rewrap.
They are the same container and, here, the same codec — HEIC is conventionally the name for the HEVC-coded variant of HEIF, and it is the format Apple has used for iPhone captures since iOS 11. The practical difference is the file extension, and some software is fussy about it. If an app specifically wants .heic, use AVIF to HEIC instead of this page.
Because HEIF was never a web image format. Chrome, Edge and Firefox do not decode it, and it does not appear among the image types those browsers document as supported. Its home is the operating system: Apple Photos, iOS and macOS apps, and device camera pipelines. If you need something that opens anywhere, keep the AVIF or produce a JPG from your AVIF.
Yes. HEIF stores alpha as an auxiliary image item in the same way AVIF does, so a transparent or partially transparent AVIF converts without being flattened onto a background. This is the main advantage over converting to JPEG, which has no alpha channel at all and must composite transparent pixels onto a solid colour.
You get the first frame as a single still. HEIF can carry image sequences in principle, but this conversion produces a still image, so an animated AVIF is reduced to one frame. If you need to keep the motion, target an animation format instead — AVIF to APNG or AVIF to GIF.
Usually not by much, and often slightly larger at the same visual quality. AV1 and HEVC are close in efficiency, with AV1 generally holding a small edge at low bitrates, so converting for size alone is not worth doing. Convert for compatibility with HEVC-based software; if you want a genuinely smaller file, lower the Quality Preset or set a Specific file size target instead.
No. Files travel over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours together with the HEIF we produce. There is no sign-up, no watermark, and nothing is shared or made public.