Every image you ship to the web gets rendered twice: once when you optimize it, and again by the browser. Pick the wrong format and you're either leaving performance on the table or fighting tooling support. In 2026, the two formats worth your attention are WebP and AVIF. Both beat JPEG on compression. Both support transparency. Both have broad browser support. The question is which one to reach for first — and when to use both together.
If you're new to image optimization, our WebP conversion guide covers the basics of why modern formats matter. This post goes deeper on the WebP-vs-AVIF tradeoff.
Key Takeaways
- WebP cuts file sizes by 25–34% vs JPEG at equivalent quality (Google WebP Compression Study)
- AVIF achieves roughly 50% smaller files than JPEG in Netflix's published benchmarks
- AVIF beats WebP by approximately 15–20% at equivalent quality settings — content-dependent
- Browser support: WebP is universal (Chrome 32+, Firefox 65+, Safari 14+); AVIF reached all major browsers by Safari 16 in 2022
- Default to WebP; layer AVIF on top with
<picture>for hero images and LCP candidates
What Is WebP?
WebP was developed by Google and publicly released in 2011, built on technology from the On2 VP8 codec. It supports lossy and lossless compression, alpha transparency, and animation — making it a genuine JPEG + PNG + GIF replacement in a single format.
Google's published research shows WebP achieves 25–34% smaller file sizes than equivalent JPEGs at the same perceptual quality. Gains vary with content — photos with gradients and rich colour compress well; flat-colour graphics may compress even better using lossless WebP.
Browser support (2026): Chrome 32+, Firefox 65+, Safari 14+, and all Chromium-based browsers. WebP is effectively universal today.
What Is AVIF?
AVIF (AV1 Image File Format) was finalised in 2019 by the Alliance for Open Media — a consortium that includes Netflix, Google, Apple, Microsoft, and Amazon. It is built on keyframes from the AV1 video codec and brings significantly stronger compression than WebP.
Netflix's engineering research showed AVIF achieving roughly 50% smaller file sizes than JPEG at comparable perceptual quality. Independent benchmarks from Google's Squoosh project show AVIF beating WebP by approximately 15–20% at equivalent quality settings — though results are highly content-dependent.
AVIF also supports HDR, wide colour gamut (Display P3, Rec. 2020), and 10/12-bit colour depth — capabilities that matter for high-fidelity photography and premium e-commerce product shots.
Browser support (2026): Chrome 85+ (2020), Firefox 93+ (2021), Safari 16+ (2022), and all Chromium-based browsers. All major browsers support AVIF.
Head-to-Head Comparison
| Feature | WebP | AVIF |
|---|---|---|
| Compression vs JPEG | ~25–34% smaller | ~40–50% smaller |
| Transparency | Yes | Yes |
| Animation | Yes | Limited tooling |
| HDR / wide colour gamut | No | Yes |
| Lossless | Yes | Yes |
| Encoding speed | Fast | Slower (improving) |
| Browser support | Universal | All major browsers |
| Tool support | Excellent | Good and growing |
When to Use WebP
WebP is the right default for most web projects:
- Speed matters in your pipeline. WebP encodes dramatically faster than AVIF, which matters when you're processing hundreds of product images in a build step or CI pipeline.
- You need animation. WebP animation tooling is more mature and widely supported than AVIF's equivalent.
- Broad compatibility with zero configuration. Safari has supported WebP since 2020; you can serve it without a
<picture>fallback in most modern projects. - Predictable results. WebP compression behaviour is well understood, and quality settings map reliably to output size.
When to Use AVIF
AVIF is worth the added complexity when file size is the priority:
- Hero images and LCP candidates. Your Largest Contentful Paint image directly affects Core Web Vitals. Shaving 20–30% off that file size is a meaningful win.
- E-commerce product photography. High-fidelity product shots — fine texture, specular highlights, accurate colour — benefit most from AVIF's superior detail retention and wide-gamut support.
- Image-heavy pages. Blogs, portfolios, and galleries where cumulative image weight compounds across dozens of assets.
- HDR displays. AVIF is the only web image format that properly supports HDR and Display P3 colour — important for photography portfolios on modern Apple and OLED displays.
Use Both With <picture>
The cleanest production approach: serve AVIF to browsers that support it, WebP as the fallback. The HTML <picture> element handles this with no JavaScript and no runtime cost:
<picture>
<source srcset="hero.avif" type="image/avif" />
<source srcset="hero.webp" type="image/webp" />
<img src="hero.jpg" alt="Hero image" loading="lazy" width="1200" height="630" />
</picture>
Browsers pick the first <source> they support and ignore the rest. The <img> fallback ensures compatibility with any environment that supports neither. This is a zero-cost pattern — pure declarative HTML.
Practical Recommendations
- Default to WebP for everything. It's supported everywhere, compresses well, and your tooling already handles it.
- Add AVIF for your top LCP images. Run your hero and above-the-fold images through an AVIF encoder, wrap them in
<picture>, and measure the Core Web Vitals delta in PageSpeed Insights. - Never re-encode lossy to lossy. Start from the original uncompressed source. Each generation of lossy re-encoding stacks visible artefacts.
- Target 150–200 KB for hero images, under 100 KB for thumbnails. These are practical starting points for fast-loading pages — adjust based on your measured LCP and layout shift budget.
Try It Right Now
You don't need Photoshop or a build pipeline to test either format. Use our free image compressor to convert and compress images to WebP directly in your browser — no upload, no account, no file size limit. Your files never leave your device.
Convert a hero image, compare the output sizes, and the format choice becomes obvious. For a step-by-step walkthrough of WebP conversion specifically, see our WebP conversion guide.