Pick the wrong image format and you either ship megabytes you don’t need, or you ship artifacts that ruin a crisp logo. The right call depends on what the image is, how much you can compress it, and which browsers you still support. Here is how PNG, JPG, WebP, and AVIF actually compare in 2026.
The core trade-off: lossless vs lossy
Every raster format is either lossless (preserves every pixel exactly) or lossy (discards detail to shrink the file). That single decision drives most of the rest:
- Lossless — PNG, lossless WebP, lossless AVIF. Use when pixels must be exact: UI elements, screenshots with text, logos with sharp edges.
- Lossy — JPG, lossy WebP, lossy AVIF. Use for photographs and complex imagery where the eye tolerates compression.
JPG has no lossless mode. PNG has no lossy mode. WebP and AVIF do both, which is a big part of why they have displaced the older formats for web delivery.
PNG: when pixels must be exact
PNG is lossless and supports full alpha transparency. It remains the right choice for:
- Logos, icons, and UI graphics with sharp edges and flat color
- Anything that needs transparency
- Screenshots where text must stay crisp
The cost: PNG photos are large. A photograph exported as PNG is routinely 5–10× the size of the same image as JPG.
JPG: the legacy default for photos
JPG (JPEG) is lossy and does not support transparency. It is still universally supported and produces small files for photographs. Its weaknesses are well known:
- No alpha channel
- Visible blocking artifacts at high compression
- Generational loss: every re-save degrades quality
JPG remains useful as a fallback format for the small slice of browsers that don’t support WebP or AVIF, and for user-uploaded photos you don’t want to re-encode.
WebP: the sensible default in 2026
WebP supports both lossy and lossless compression, alpha transparency, and animation. Modern WebP files are roughly 25–35% smaller than JPG at equivalent visual quality and noticeably smaller than PNG for the same content.
Browser support for WebP now sits at roughly 96% globally per Can I Use, including Safari (since version 14 on macOS Big Sur, with full maturity by Safari 16). For most audiences, WebP is safe to ship as the primary format.
When to reach for WebP:
- Photographic hero images and product shots
- Any image currently shipped as JPG where you want a free size win
- Situations where you want one format that covers both photos and graphics with transparency
AVIF: best compression, newer tooling
AVIF (AV1 Image File Format) typically beats WebP on file size — often 20–50% smaller than WebP at comparable quality, especially for photographic content. It supports lossy and lossless modes, alpha, and animation.
Global AVIF support is now around 93–95% per Can I Use, including Chrome 85+, Firefox 93+, Safari 16.1+, and Edge 121+. The remaining gaps are older iOS and legacy Edge.
AVIF’s trade-off is encoding cost: it is noticeably slower to encode than WebP, particularly at high quality settings. For a build pipeline that encodes thousands of images, that matters. For a one-off export, it doesn’t.
When to reach for AVIF:
- You want the smallest possible file and can tolerate longer encode times
- Bandwidth is expensive (large CDN bills, mobile-first audiences)
- You already serve
<picture>with multiple sources
Browser support at a glance (2026)
| Format | Global support | Notable gaps |
|---|---|---|
| PNG | ~100% | None |
| JPG | ~100% | None |
| WebP | ~96% | Older iOS/macOS, very old browsers |
| AVIF | ~93–95% | Older iOS (<16), legacy Edge |
Both modern formats are production-safe. Serve a JPEG or PNG fallback through the <picture> element if you need to cover the last few percent.
The practical recommendation
Default to WebP. It is the boring, safe choice in 2026 — broad support, good compression, and tooling everywhere.
Reach for AVIF when you want maximum compression or you already run a <picture> pipeline that can serve both formats and let the browser pick.
Keep PNG for logos, icons, and anything where transparency and pixel-exact edges matter.
Keep JPG as a fallback and for user uploads you don’t transcode.
Responsive images: don’t forget srcset
Format choice is half the battle; the other half is not shipping a 4000px image to a phone. Use srcset and sizes so the browser picks an appropriately sized source:
<picture>
<source type="image/avif" srcset="hero-800.avif 800w, hero-1600.avif 1600w">
<source type="image/webp" srcset="hero-800.webp 800w, hero-1600.webp 1600w">
<img src="hero-800.jpg" srcset="hero-800.jpg 800w, hero-1600.jpg 1600w"
sizes="(max-width: 800px) 100vw, 1600px"
alt="Hero photograph" width="1600" height="900" loading="lazy">
</picture>List AVIF first, then WebP, then a JPG <img> fallback. The browser uses the first source it understands and ignores the rest.
If you want to convert assets between formats and see the size difference for your own images, run them through an image format converter and then push the result through an image compressor to find the quality setting that hits your size target without visible artifacts.