You upload a photo to your site, it looks fine, and then you run a Lighthouse audit. The first recommendation staring back at you: serve images in next-gen formats. That's WebP they're talking about.
WebP is an image format Google released in 2010. The pitch is simple: same visual quality, smaller file. In practice, WebP images come out 25 to 35% smaller than JPEG at equivalent quality, and roughly 26% smaller than PNG for anything with transparency. On a product page with 15 images, that adds up fast.
The compression behind it
WebP doesn't just apply a single trick. It has two distinct compression modes, and knowing which one applies to your images matters.
Lossy WebP is built on top of VP8, Google's video codec technology. It works similarly to JPEG in that it throws away visual data the eye won't notice. But it does it more efficiently. A WebP photo that looks identical to a JPEG will typically be a third smaller. The codec is better at encoding smooth gradients, skin tones, and natural textures without the blocky artifacts JPEG tends to produce at lower quality settings.
Lossless WebP is a different story. Every pixel is preserved exactly. No data is thrown away. For logos, screenshots, UI assets, anything where accuracy matters more than compression ratio, lossless WebP replaces PNG and usually beats it on file size.
Both modes support transparency (a proper alpha channel, not the 1-bit hack GIF uses). And WebP also handles animation, which makes it a legitimate replacement for GIF files that have no business being served in 2026.
Where things get tricky
WebP isn't perfect. The format does have real limitations.
Email clients are the main problem. Most of them don't render WebP. If you're producing images that will be shared via email or embedded in newsletters, stay with JPEG or PNG. Same goes for messaging apps: WhatsApp, Telegram, and others will usually accept WebP, but some older desktop clients won't display it correctly.
Image editing software has caught up significantly, but not entirely. Photoshop supports WebP natively now, as does Figma and most browser-based tools. Older versions of Lightroom don't. If your workflow depends on software that can't open WebP, you'd have to convert back to an editable format before making changes, which defeats the point.
For archiving originals, WebP isn't the right choice either. If you're storing a master file, keep it as a lossless PNG or an original RAW. WebP is an export format, a delivery format. It's what you put on the server, not what you keep in your archive.
Browser support, honestly assessed
Every major browser has supported WebP for years. Chrome, Edge, Firefox, Opera, and Safari since version 14 (late 2020). Mobile browsers are fully covered.
The only edge case worth mentioning is very old Safari versions, pre-2020. If your analytics show a meaningful share of those users, you'd want an HTML <picture> element with a JPEG fallback. If they represent less than 1% of your traffic, you can safely ignore it and serve WebP to everyone.
When the switch is worth it
The clearest wins are photos and product images on web pages. If you're serving JPEG files through a CDN or a CMS, converting them to WebP before upload is one of the cheapest performance improvements available. No code changes, no infrastructure work. The file just loads faster.
Transparent PNGs are the second obvious case. Icons, overlays, interface graphics with transparent backgrounds: lossless WebP handles all of this, and the files come out smaller.
Animated GIFs are where the savings get dramatic. A GIF that's 2MB can often be converted to WebP animation under 200KB without any visible quality loss. GIF compression is genuinely bad by modern standards.
| Format | Lossy | Lossless | Transparency | Animation |
|---|---|---|---|---|
| JPEG | Yes | No | No | No |
| PNG | No | Yes | Yes | No |
| GIF | No | Yes | 1-bit only | Yes |
| WebP | Yes | Yes | Yes | Yes |
A practical note on quality settings
When converting to lossy WebP, quality 80 is a reasonable default for photos. Below 70, you'll start seeing compression artifacts. Above 90, the file size gains shrink fast and you're mostly paying for almost-imperceptible improvements.
For lossless WebP, quality settings control compression effort rather than visual fidelity. Higher settings produce smaller files at the cost of encoding time. For batch conversions, quality 75 to 85 is a practical balance.
WebP is the format the web settled on for a reason. It covers the use cases that previously required three different formats, it's supported everywhere that matters, and the file size reduction is real and meaningful. The main question isn't whether to switch, it's which images to start with.