WebP vs AVIF vs JPEG XL: Choosing a Modern Image Format

Three successors to JPEG, one decision

If you run a website in 2026, you have three credible replacements for JPEG and PNG: WebP, AVIF, and JPEG XL. All three compress better than the formats they replace, all support transparency, and all are free to use. They differ sharply in how much they save, how long they take to encode, and — most importantly — where they can actually be viewed. Picking the wrong one either leaves bandwidth on the table or ships images some visitors cannot see.

This guide compares the three on the axes that matter in practice — compression, browser support, encode speed, and features like HDR — and ends with concrete recommendations by use case.

Compression efficiency: what you actually save

WebP is the oldest and least efficient of the three, but it is still a meaningful upgrade over JPEG — typically 25 to 35 percent smaller at comparable visual quality. Its main weakness is at the high-quality end: lossy WebP is limited to 4:2:0 chroma subsampling, so fine color detail — red text on a dark background, saturated product shots — can smear slightly.

AVIF, built on the AV1 video codec, is the efficiency leader for typical web delivery. It routinely produces files around half the size of an equivalent JPEG, and its advantage grows at lower quality settings — AVIF degrades into soft, plausible-looking images rather than blocky JPEG artifacts. That makes it especially strong for hero images and thumbnails, anywhere you will trade a little fidelity for a lot of bandwidth.

JPEG XL sits in a different sweet spot: high fidelity. At quality levels where compression is invisible, JXL usually beats AVIF, and its lossless mode is the best general-purpose lossless image compressor in wide use — noticeably smaller than PNG. It also has a unique trick: it can losslessly recompress an existing JPEG, typically shaving around 20 percent off the file size while remaining bit-for-bit reversible to the original. No other format can do that.

Browser support in 2026: the deciding constraint

This is where the comparison stops being close. WebP has been safe to ship without a fallback for years — every current browser decodes it, and support reaches back far enough to cover even long-outdated devices. If you need exactly one format and zero surprises, WebP is it.

AVIF reached full coverage across Chrome, Firefox, Safari, and Edge, so for visitors on evergreen browsers it is effectively universal. The remaining gaps are older devices that stopped receiving browser updates. A picture element with a JPEG or WebP fallback covers those cleanly, and most image CDNs will negotiate the format automatically via the Accept header.

JPEG XL is the hard case. Safari supports viewing it; Chrome and Firefox do not ship a decoder in their release versions, despite years of debate and a technically excellent format. That means you cannot serve JXL to the open web as your only copy of an image — most visitors would see nothing. Treat JXL browser support as Safari-only until that actually changes, not as something to bet a redesign on.

Encode speed and workflow cost

WebP encodes fast — fast enough to generate on the fly on a modest server or convert hundreds of images in a browser tab. JPEG XL is also quick at its default effort settings, and its lossless JPEG recompression is nearly instant because it reuses the existing JPEG data rather than re-encoding pixels.

AVIF is the slow one, and the gap is not subtle. AV1 encoding does an enormous amount of work searching for the best compression, so a large photo can take many times longer to encode as AVIF than as WebP or JXL. For a build pipeline that processes images once and serves them forever, that cost is worth paying. For anything interactive or high-volume — user uploads, on-demand resizing without a cache — encode time becomes a real engineering constraint. AVIF is also somewhat heavier to decode than WebP, which is measurable on low-end phones, though rarely a dealbreaker.

Transparency, HDR, and everything else

All three support an alpha channel, so any of them can replace transparent PNGs — usually at a fraction of the size. For flat graphics and UI assets, lossless WebP is a dependable PNG replacement; JXL lossless is typically smaller still if your viewers can decode it.

HDR and wide color gamut are where WebP shows its age. It is an 8-bit format, full stop. AVIF supports 10- and 12-bit color with the PQ and HLG transfer functions, which is why it has become the practical choice for HDR photos on the web. JPEG XL goes further, supporting up to 32-bit floating-point channels, very large image dimensions, and progressive decoding — the image sharpens as it loads, the way progressive JPEGs did, which AVIF cannot do. For archival and professional photography pipelines, that feature set is why many people consider JXL the best-designed of the three.

Recommendations by use case

General website images: serve AVIF with a WebP or JPEG fallback via the picture element, or let your CDN negotiate formats for you. You get AVIF savings for nearly everyone and a guaranteed fallback for the rest. If maintaining two encoded copies is more complexity than the project justifies, plain WebP everywhere is a defensible choice — universal, fast to produce, and still a solid improvement over JPEG.

Photography at high quality: JPEG XL where you control the viewing environment — your own archive, an app you build, or an Apple-only audience. For shrinking a collection of existing JPEGs without any quality loss, JXL recompression is the standout option. For HDR images on the open web today, use AVIF.

Transparent graphics, logos, screenshots: lossless WebP for delivery, JXL lossless for storage. Reserve PNG for tooling that accepts nothing else.

You can test all of this on your own images with Convertmaxxing — convert a few representative photos to each format at different quality settings and compare the results yourself. Everything runs in your browser via WebAssembly, so files never leave your device, there is no signup, and it is free. One honest note: AVIF encoding is slow here too, so give large images a moment.