WebP has been the de facto 'modern format' since Chrome adopted it in 2014 and Safari finally joined in 2022. But AVIF — derived from the AV1 video codec — has rapidly matured into a serious competitor. If you are building or optimizing a website in 2026, choosing between them is no longer theoretical.
File Size: AVIF Wins on Paper
In controlled benchmarks, AVIF consistently produces files 20-30% smaller than WebP at equivalent perceptual quality (measured by SSIM or VMAF scores). For a 1200px hero image that encodes to 85KB in WebP lossy, AVIF typically achieves 60-70KB with no visible difference at normal viewing distance.
The gap narrows for simple graphics and widens for photographic content with complex textures. If your site is photo-heavy (portfolios, e-commerce product shots, editorial), the savings compound significantly across hundreds of images.
Encoding Speed: WebP Has the Edge
AVIF encoding is computationally expensive. Converting a batch of 50 images to AVIF takes roughly 3-5x longer than the same batch to WebP. In web-based tools using WebAssembly, this translates to noticeable waits on lower-end hardware.
For build-time optimization (CI/CD pipelines, static site generation), this rarely matters — you encode once and serve forever. For real-time workflows where you need quick conversions during a work session, WebP's speed advantage is practical.
If you are batch-converting for a website, encode to both formats and serve AVIF with a WebP fallback using the HTML <picture> element. This gives you the best compression where supported and guaranteed compatibility everywhere else.
Browser Support in 2026
WebP enjoys universal support — every browser that matters (Chrome, Firefox, Safari, Edge, Samsung Internet, Opera) has supported it for years. It is the safe default choice.
AVIF support is now above 93% of global web traffic (caniuse.com data). Chrome, Firefox, and Samsung Internet have full support. Safari added AVIF support in version 16.4 (2023). The remaining gap is mostly older iOS devices that have not updated and niche browsers.
Quality Characteristics
WebP tends to produce subtle banding artifacts in smooth gradients at lower quality settings. AVIF handles gradients significantly better due to its more advanced perceptual model.
For sharp text and UI screenshots, WebP lossless is excellent and well-tested. AVIF lossless exists but produces slightly larger files than WebP lossless in many cases — an area where WebP retains an advantage.
Practical Recommendation
- Use AVIF as primary for photographic content where encoding time is not a constraint.
- Use WebP as primary for graphics, screenshots, and anything requiring fast encoding.
- Use both via <picture> element for maximum savings with full compatibility.
- Keep JPEG as a final fallback only if you must support very old browsers or email clients.
The format war is effectively over — both are excellent. The right choice depends on your content type, workflow speed requirements, and willingness to serve multiple formats. For most sites, WebP alone is a massive improvement over JPEG/PNG and the simplest path forward.