AVIF and WebP are the two modern formats fighting to replace JPG and PNG on the web. Both support lossy and lossless modes, transparency, and animation. AVIF (based on AV1 video compression) is smaller — typically 20% smaller than WebP at equivalent visual quality. The trade-offs are decode cost, encode cost, and slightly lower browser coverage.
WebP has universal modern-browser support (since Safari 14 in 2020, ~98% global coverage). AVIF support arrived later (Safari 16 in 2022) and sits around 93%. For high-traffic sites the 5-percentage-point gap matters; for most sites either is fine with a fallback.
Decode cost is the real differentiator. AVIF is 2–3× slower to decode than JPG; WebP is 1.5× slower than JPG. On extremely image-heavy pages on older mobile devices, AVIF's decode cost can outweigh its smaller download. For typical web use, both formats decode fast enough that download time dominates.
Spec comparison
| Property | AVIF | WebP |
|---|---|---|
| Compression | Both | Both |
| Graphic type | Raster | Raster |
| Transparency | Yes | Yes |
| Animation | Yes | Yes |
| HDR | Yes | No |
| Embeds EXIF | Yes | Yes |
| Browser coverage | 93% | 98% |
| Introduced | 2019 | 2010 |
File size comparison
Same 1920×1280 photographic content
AVIF
AVIF at q60: ~140 KB
WebP
WebP at q80: ~180 KB
AVIF's quality scale is calibrated differently from WebP — AVIF q60 is roughly equivalent to WebP q80 visually. The 22% size advantage is typical; AVIF widens its lead on larger images and on smooth gradients.
Quality comparison
At equivalent visual quality, AVIF and WebP look identical. AVIF handles fine detail (foliage, fabric textures, fur) noticeably better than WebP at very aggressive compression settings (below WebP q60). At normal web-quality settings, both formats are visually clean.
When each one wins
Use AVIF if…
- Bandwidth cost is a material constraint (high-traffic site, mobile-heavy audience)
- You can deploy a WebP or JPG fallback via <picture>
- Your static site build can afford the slower AVIF encode time
- Your audience skews modern-browser (less of an issue every year)
Use WebP if…
- You want the safest modern default — WebP's tooling and browser support are more mature
- You're encoding dynamically (avatar processing, on-the-fly thumbnails) — WebP encodes 10× faster than AVIF
- You're not yet ready to deal with the AVIF fallback complexity in your CMS or theme
- Older mobile devices are a meaningful share of your traffic
Recommendation
WebP is the right default for most sites in 2026 — mature tooling, ubiquitous browser support, fast encode. Add AVIF if you're optimising for bandwidth at scale and have engineering resource to maintain a <picture>-based fallback chain. Most sites get 90% of the benefit from migrating JPG → WebP; the AVIF upgrade pays off mainly on high-traffic sites where small percentage-point gains compound.
Frequently asked questions
- Is AVIF really better than WebP?
- For file size, yes — about 20% smaller at equivalent quality. For practicality today, WebP still wins on encoding speed, tooling maturity and browser coverage. The right answer depends on whether the size advantage is worth the trade-offs for your site.
- Why is AVIF encoding so slow?
- AVIF uses AV1 video compression for still images. AV1 prioritises compression ratio over encoding speed. At default effort settings, AVIF encoding is 10–30× slower than WebP. For static site builds this is a one-time cost; for dynamic image processing it matters.
- Should I serve AVIF, WebP, or both?
- Both, via <picture>. The browser picks AVIF if it can render it, falls back to WebP if not, falls back to JPG/PNG for legacy clients. Build tools like Next.js Image, Cloudflare Images and most modern CDNs handle this automatically.
- Does AVIF work in Safari?
- Safari 16+ (released September 2022) supports AVIF. Older Safari and iOS versions need a fallback.
- Will my CMS break if I upload AVIF?
- Possibly. WordPress 6.5+ supports AVIF natively; older themes may not. Shopify's CDN auto-serves AVIF where supported. Test your specific stack — for many setups, sticking with WebP avoids the friction.