Most websites still use JPG and PNG images. Those formats date from the '90s and 2000s and work fine, but they're technically outdated. WebP and AVIF are their modern successors.
The big advantage: to the human eye they look identical, but the files are 40 to 70% smaller. An 800 KB photo can suddenly become 250 KB without any visible loss in quality.
Why does that matter?
Smaller files = faster loading. And loading speed is a direct ranking factor for Google. Sites that go from 5 seconds to 2 seconds often see noticeable ranking improvements within weeks.
On top of that, people on mobile with a poor 4G connection drop off faster if your site loads slowly. Every extra second of loading time costs roughly 7% in conversions. If you get 100 visitors a day, that's 7 potential customers lost every day because of slow images.
Does it work everywhere?
WebP has been supported by all browsers (Chrome, Firefox, Safari, Edge) since 2020. AVIF is newer still, but almost all browsers support it by now. The rare visitor with an outdated browser automatically falls back to the original JPG/PNG.
How do you turn it on?
Two ways:
- Automatically through your hosting provider or CDN. Some hosting providers (such as Cloudflare or modern WordPress hosts) automatically convert all your images to WebP as they load. Then you don't have to do anything yourself.
- Converting by hand. Use a free tool like squoosh.app: drag your JPG in, click 'convert to WebP', download the result and upload it to your site. Works well for 5-10 images, less practical for hundreds.
How do you check whether your site already uses it?
Right-click an image on your site, click 'open in new tab', and look at the URL at the top. Does it end in .webp or .avif? Then you're using modern formats. Does it end in .jpg or .png? Then there's still something to gain.