JPG to WEBP

This one is almost always about performance. Images are the heaviest thing on a typical web page by a wide margin, and Core Web Vitals — Largest Contentful Paint in particular — are dominated by how fast the main image arrives. WebP gets you a meaningful size reduction without the visible artefacts you would get by simply cranking JPG compression harder, because its encoder is a generation newer and works in larger, smarter blocks. The compatibility objection that used to hold people back has essentially evaporated: Chrome, Firefox, Edge, Opera and Safari all decode WebP, which covers effectively every visitor you have. The remaining caution is about where the file will end up. WebP is for serving on the web; it is still a poor choice for archiving or for handing to a print shop.

Convert copies destined for the web and keep your camera files as they are. A JPG has already been compressed lossily once, and re-encoding it to WebP compresses it again — the result looks fine on a web page but it is a generational step down, and it is not something you can undo later. Treat WebP as an output format, the same way you would treat a resized thumbnail, rather than a replacement for your library.

Around 0.80 to 0.85 is the sweet spot for photographs on a website, and it is where the size saving is most dramatic relative to the visual cost. Push toward 0.92 and above for hero images, product photography or anything a customer will zoom into. Below about 0.70 the encoder starts smoothing away fine texture — skin, foliage and fabric are where you notice it first. Convert one representative image, look at it properly, and then run the batch at that setting.

If you support genuinely ancient clients, the standard approach is an HTML picture element listing the WebP first and the original JPG as a fallback source, letting each browser take what it understands. Most modern site builders, CDNs and CMS platforms now handle this negotiation for you automatically, so check whether yours already does before adding markup by hand.

JPG (also written JPEG) has been the default photograph format since 1992. It uses lossy compression tuned for the way human vision works — discarding fine colour detail the eye barely registers — which is why a photo saved as JPG can be a tenth the size of the same image as PNG. The trade-off is that it has no transparency channel and that every re-save degrades the image slightly, so it suits finished photographs rather than working files.

WebP is Google's 2010 image format, and it is unusual in offering both lossy and lossless modes plus transparency in a single container. In practice it lands roughly 25–35% smaller than an equivalent-quality JPG, which is why it spread quickly across the web once Safari added support in 2020. Its weakness is outside the browser: plenty of desktop software, older phones and printing workflows still will not open a .webp file.