Got a folder full of old JPG photos weighing your website down? Drop one in here and get a WebP back that's roughly a third smaller — with no visible difference in quality, and no waiting in an upload queue.
JPEG has been around since 1992, and it shows. Push a JPG's compression a bit too far and you get those familiar blocky patches, washed-out color bands, and fuzzy edges around text. It was built for a different era of the web.
WebP works differently. Instead of treating every block of pixels on its own, it looks at the blocks around each one and only stores what's actually different between them. That's the trick behind its compression — same photo, visibly the same quality, but roughly a third lighter in file size. On a page with a dozen images, that difference adds up fast.
The browser unpacks your JPEG into raw pixels right there in memory. No server gets involved at any point.
The raw pixels are compressed again — this time with WebP's smarter prediction method — using whatever quality setting you've picked.
The finished WebP file is packaged up and offered for download straight from your browser. Nothing is stored anywhere.
| Metric | JPEG / JPG | WebP | What It Means for You |
|---|---|---|---|
| Compression Base | Discrete Cosine Transform (8x8) | VP8 Intra-Prediction (16x16 / 4x4) | Smarter, more efficient encoding |
| Relative File Size | Baseline (100%) | 65% – 75% of JPEG | ~30% less bandwidth used |
| Transparency (Alpha) | Not Supported | Supported (8-bit Channel) | Can replace heavy PNGs too |
| Browser Compatibility | 99.9% Universal | 97.8% (All Modern Browsers) | Safe to use on live sites |
Indirectly, yes. Google measures how fast your pages load — especially the biggest image on screen (called Largest Contentful Paint). Heavy hero JPGs are usually the main culprit behind slow scores. Shrink them by 30% with WebP and those numbers improve, which is exactly the kind of thing Google's page experience signals reward.
Between 80% and 85% is the sweet spot. The human eye can't spot the difference at that level, yet you'll still save well over 30% compared to the original JPG. Going below 70% starts to show on photos with gradients and faces.
Of course. WebP opens in any image editor and converts back to JPG or PNG without a fuss. But honestly, if the file is going on a website, there's little reason to go back — WebP is the better home for it.
Safer than most converters, actually. Many online tools quietly upload your file to a cloud server, process it, and delete it later — hopefully. Here, nothing is sent anywhere at all. The conversion happens inside your own browser, and once you close the tab, it's gone.