WEBP vs AVIF vs JPEG XL — The 2026 Comparison

Three modern image formats compete for the position once held uncontested by JPEG: WEBP (from Google, around since 2010), AVIF (based on the AV1 video codec, mainstream since 2020), and JPEG XL (the most ambitious of the three, finalised in 2022 but only recently widely supported). Choosing among them in 2026 is no longer obvious — each has specific strengths and the right answer depends on what you are building.

This article compares all three on the dimensions that actually matter: compression efficiency at matched quality, encoding and decoding speed, browser support, and feature coverage (transparency, animation, lossless mode, progressive decoding, HDR).

Compression efficiency

For typical photographs at perceptually identical quality, the rough ranking is JPEG XL ≈ AVIF > WEBP > JPEG. AVIF tends to win for very low-quality settings (where its block-based structure is more aggressive), JPEG XL tends to win for medium and high quality (where its variable-block-size DCT and ANS entropy coding shine), and WEBP sits 20–30% behind both at most quality levels.

Concrete numbers from a recent Cloudinary-style benchmark on a 5,000-image set: AVIF was about 50% smaller than JPEG at SSIM-matched quality, JPEG XL about 55% smaller, WEBP about 30% smaller. Those numbers vary widely by content type — JPEG XL is dramatically better than the others on text-heavy images and screenshots, AVIF is dramatically better on smooth gradients (skies, sunsets).

Encoding speed

AVIF is slow to encode. Even with libavif's "fast" preset, encoding a 12-megapixel image takes 2–5 seconds on a modern CPU. The "quality" presets that produce truly small files take 30 seconds or more. This is fine for a static image you encode once and serve millions of times, but it is a problem for any workflow that encodes on demand.

JPEG XL encodes about 5–10× faster than AVIF at similar quality levels. The reference encoder is well-optimised, and SIMD paths exist for x86 and ARM. WEBP is the fastest of the three, encoding a 12-megapixel image in well under a second.

For decoding the order is reversed: WEBP and JPEG XL decode in a few hundred milliseconds, AVIF takes longer because the AV1 decoder has more steps. On low-end mobile devices this can matter — a page with twenty AVIF images can have noticeable decode-stutter that the same page in WEBP or JPEG XL avoids.

Browser support in 2026

• WEBP: universal. Every browser that anyone uses supports it.
• AVIF: universal in current browsers. Safari added support in 16.0, Chrome and Firefox have had it since 2020. The remaining concern is older devices that won't update — about 3% of global traffic at this point.
• JPEG XL: support is now genuinely good but uneven. Safari 17+ supports it. Chrome restored support behind a flag in 2024 and unflagged it in 2025. Firefox has had it since 2024. Older Chrome versions (a long tail of unupgraded Android) still don't support it.

For public-facing websites in 2026, the safe play is still: serve AVIF as primary, WEBP as fallback, JPEG as final fallback. Use the <picture> element to let the browser pick. JPEG XL can be added to the chain ahead of AVIF if you measure your audience and find the support is sufficient.

Feature coverage

All three support lossless mode, alpha transparency, and animation, but with different strengths.

Lossless: JPEG XL has the best lossless compression, often 20% smaller than PNG. WEBP lossless is also excellent (often 25% smaller than PNG). AVIF lossless exists but is poorly supported by encoders and tends to produce larger files than the other two.

Animation: WEBP has the best tooling for animated images — most GIF-replacement tools target animated WEBP. AVIF supports animation via its AV1 underpinnings but tooling is weaker. JPEG XL supports animation but few encoders implement it well.

HDR / wide gamut: AVIF was designed with HDR in mind and is the best choice for HDR photos. JPEG XL also supports HDR but encoder maturity lags. WEBP supports only standard dynamic range.

Progressive decoding: JPEG XL has true progressive decoding (you can show a low-quality preview while the rest loads, like classic progressive JPEG). AVIF has no progressive mode by design — the entire image must download before any pixel can be shown. WEBP also lacks progressive mode. For above-the-fold images on slow connections, JPEG XL has a real perceived-performance advantage.

Lossless JPEG transcoding: JPEG XL has a unique feature: it can losslessly transcode existing JPEG files to a 20% smaller JPEG XL file, and back to the original JPEG bit-for-bit if needed. This makes JPEG XL the only safe choice for archives where you might need to recover the original later.

Practical recommendations for 2026

For a typical website

Use AVIF as the primary format with WEBP fallback. Don't bother with JPEG XL yet for public sites — the support is good but not yet at the level where the encoding hassle is worth it for the few percent of users who get the better experience. Use the <picture> element with explicit type hints so the browser picks the best supported format without any client-side detection logic.

For an internal tool or app

If you control the browser version your users have (intranet, kiosk, packaged Electron app), you can pick whichever format gives you the best size. JPEG XL is excellent for document-heavy applications because of its strong performance on text and screenshots.

For long-term archival

JPEG XL, with the lossless JPEG transcode feature. You get the size savings of a modern format without giving up the ability to recover original JPEGs if format support shifts.

For UI assets (icons, illustrations)

SVG when possible. When a vector format isn't feasible (rich illustrations with photographic textures), WEBP lossless beats PNG significantly while being universally supported.

For animated content replacing GIF

Animated WEBP. Tooling is strongest, support is universal, and the size advantage over GIF is enormous (often 10× smaller). For longer animations consider an actual video format (MP4, WebM) — they will be smaller still.

A common mistake: re-encoding

Every time you re-encode a lossy image, you lose quality. Going from JPEG to WEBP and then to AVIF compounds the loss. The right pipeline is: keep your originals as lossless masters (PNG, TIFF, or JPEG XL lossless), and encode to your delivery format from the master each time the encoder updates or you change quality settings. Re-encoding from already-compressed sources should be a last resort.

Privacy and tooling

Most online image converters upload your image to a server. For personal photos and especially for images containing identifiable people, this is a privacy decision worth making consciously. Toolkiya's image converter runs entirely in the browser using WebAssembly builds of the reference encoders. Your photo never touches a server, and the conversion runs at near-native speed thanks to SIMD and threads.

Closing thought

The image format question is finally a matter of trade-offs rather than waiting for support. AVIF wins on raw compression for photographs, JPEG XL wins on features and transcoding, WEBP wins on tooling and ubiquity. For most websites in 2026, the answer is "AVIF with WEBP fallback" — but the answer is no longer the same answer for every use case, and that is a good problem to have.