AVIF vs HEIC vs WebP: How the Modern Image Formats Differ

WebP is the oldest of the three. Google announced it in September 2010, a few months after buying On2 Technologies, whose VP8 video codec became the engine of the new format. The idea was simple: a still WebP is essentially one VP8 keyframe in a small RIFF wrapper. The first version was lossy only. A lossless mode, an alpha channel for transparency and animation followed over the next three years, which is why WebP can replace JPG, PNG and GIF with one file type. Google still documents the format and its libwebp library on the WebP developer site.

HEIC has a different background. HEIF, the High Efficiency Image File Format, is a container standard published by the Moving Picture Experts Group as ISO/IEC 23008-12 in 2015. A HEIF file can hold images compressed with several codecs; when the codec is HEVC, also known as H.265, the file is called HEIC. Apple made it the default camera format in iOS 11 and macOS High Sierra in 2017, on the iPhone 7 and later, and that single decision put billions of HEIC photos into circulation almost overnight. It is the reason most people ever meet the format at all.

AVIF is the newest. The Alliance for Open Media, a group founded in 2015 by Google, Mozilla, Microsoft, Amazon, Netflix, Cisco and Intel, released the royalty-free AV1 video codec in 2018 and the AVIF 1.0 image specification in February 2019. Technically AVIF borrows the HEIF container and swaps HEVC for AV1, so AVIF and HEIC are cousins with different engines. The member companies wanted a modern codec with no patent fees, and the Alliance for Open Media still publishes the AV1 and AVIF specifications.

All three formats are descended from video codecs, and that shows in how they compress. Instead of JPG's fixed 8 × 8 pixel blocks, they predict each region from neighboring pixels, use blocks of varying size and filter edges after decoding. The result is fewer blocky artifacts at low quality settings. AVIF goes furthest: at the same visual quality it typically produces the smallest file, especially on smooth skies, skin and gradients, where JPG starts to band. The price is encoding time. An AVIF can take many times longer to create than a WebP of the same photo, which matters on a phone or a busy server.

Feature support is closer than people expect. All three can store transparency, and all three have an animation mode, though animated HEIC is rare in practice. Lossless compression is where WebP stands out: its lossless mode was designed separately from the lossy one and usually beats PNG on screenshots and graphics. AVIF and HEIC can be lossless in theory, but the files tend to be large and tools rarely offer the mode. Color depth is the other big split. WebP is limited to 8 bits per channel, while HEIC and AVIF store 10-bit color, and AVIF can also carry 12-bit and HDR images.

Licensing explains much of the support story. WebP and AV1 were released royalty-free, so browser makers could add them without paying anyone. HEVC is covered by patents managed by several licensing pools, which is why Chrome, Firefox and Edge decode HEVC images only where the operating system already provides a licensed decoder. For a website owner that difference is decisive: a format every visitor can see beats one that saves a few more kilobytes for half of them.

Size differences depend on the photo, the encoder and the quality setting, so treat any number as typical rather than exact. For a 1200 × 800 px photo at quality settings that look the same on a laptop screen, a JPG is typically around 150–200 KB, a WebP around 100–140 KB and an AVIF around 60–100 KB. Google's own comparisons put lossy WebP at 25–34% smaller than JPG, and Apple describes HEIC as roughly half the size of JPG for camera photos. A 12 MP iPhone picture that would be 3–4 MB as JPG is usually 1.5–2.5 MB as HEIC.

Graphics behave differently. A screenshot with flat colors and text is often smallest as lossless WebP, followed by PNG, and AVIF gains little there. Small thumbnails also narrow the gap, because every format carries a few hundred bytes of headers. The common myths below come from reading benchmark numbers without that context.

On the web, WebP and AVIF are settled. Chrome, Edge, Firefox and Safari all display WebP; Safari was the last to join, with version 14 in 2020 on macOS Big Sur and iOS 14. AVIF arrived in Chrome 85 in 2020, Firefox 93 in 2021 and Safari 16 in 2022, and Edge added it in early 2024. A visitor on an up-to-date browser sees both. Only people stuck on old Safari versions, for example on iPhones that cannot update past iOS 15, miss AVIF, and the <picture> element lets a site send them a JPG fallback.

HEIC is the opposite story. Apple devices open it everywhere, and Safari 17 can even show it in a web page, but Chrome, Firefox and Edge do not display HEIC images on the open web. Windows 10 and 11 can open HEIC in the Photos app once you add the HEIF Image Extensions from the Microsoft Store, plus the HEVC Video Extensions on many PCs, which is a paid add-on. Recent Android versions can decode HEIF, but third-party apps and websites vary widely.

Desktop software sits in between. Adobe Photoshop has opened WebP natively since version 23.2 in 2022, and most current image viewers handle WebP. AVIF and HEIC support in editors, office suites and older programs is patchy, and many upload forms still check for .jpg, .jpeg or .png and reject everything else. The panels below summarize each platform.

For web delivery, WebP is the default answer and AVIF the optimization on top. If you control the site, serve AVIF to browsers that accept it and WebP or JPG to the rest; most image CDNs and frameworks negotiate that automatically. If you only get one file, WebP is the safer choice because every current browser shows it and it encodes quickly. For phone storage, HEIC is hard to beat on an iPhone: the camera writes it natively, the Photos app reads it, and you fit roughly twice as many pictures in the same space.

Archives, printing and paperwork pull in the other direction. A photo archive should be readable in twenty years without special codecs, which favors keeping originals as they came out of the camera and adding JPG copies where needed. Print labs typically ask for JPG or TIFF, and government, exam and job portals commonly accept only JPG or PNG, sometimes with a size cap in kilobytes. In each of those cases a converted copy is the practical answer, while the original stays in your library.

The four common jobs below sum up the decision. Choose by where the file is going, not by which format has the best benchmark.

Most conversions go one way: from a new format to JPG or PNG for compatibility. Pick JPG for photos and PNG when the image has transparency or sharp text you want to keep crisp. To convert AVIF to JPG, the converter starts at Quality 90 because web AVIF files are already compressed hard, and the Transparent areas option under Advanced settings decides what fills see-through pixels. The HEIC to JPG converter also starts at 90 and removes location data unless you untick Strip metadata.

For WebP, the WebP to JPG page starts at quality 85, which looks identical to the source at normal size. Each converter accepts up to 20 files per batch and 95 MB per file, needs no account, and deletes uploads and results 30 minutes after processing. The longer walk-throughs in how to convert HEIC to JPG and WebP to JPG: when and why cover phone settings and edge cases.

Going the other way is just as useful. If you run a site, turning JPG photos into AVIF typically cuts their weight by around half before you upload them. The matrix shows which conversions between these formats have their own converter page on UltKit.

Every lossy conversion throws away a little more detail, so convert copies, not masters. Keep the HEIC files in your iPhone library and export JPGs only for the people or programs that need them. The same applies to HDR photos: AVIF and HEIC can store 10-bit color, and converting to an 8-bit JPG maps bright highlights into the standard range, which is fine for sharing but not for later editing. If you might edit an image again, keep the original or a lossless PNG copy and do all edits from that.

Also keep the original when the newer format is already accepted. If a website builder, a chat app or a cloud drive takes WebP or HEIC directly, converting only adds a step and makes the file bigger. Convert at the edge, at the moment of upload, sending or printing, and you get compatibility without slowly degrading your library.