WebP is a modern image format developed by Google that delivers the same visual quality as JPG and PNG in a noticeably smaller file. For anyone who runs a website, that translates directly into faster page loads, better Core Web Vitals scores, and a smoother experience for visitors — all without a drop in quality the eye can detect.
This guide explains what makes WebP so efficient, walks through converting images for free in your browser, and covers the practical questions: when WebP is the right choice, when to keep a fallback, and how to combine resizing and compression for the smallest possible files.
WebP supports both lossy compression (like JPG) and lossless compression (like PNG), plus transparency and animation, all in a single format. The result is a file that does the job of three older formats while staying smaller than any of them.
You do not need Photoshop or any installed software. Open the WebP Converter, drag in your JPG or PNG, and download the WebP version. The conversion happens entirely in your browser, which means your images never leave your device — important for private photos, client work, or unpublished designs.
For a single image this takes seconds. If you have many, convert them one after another in the same tab; because nothing uploads, there is no waiting on a server and no file-count limit imposed by an account.
The single largest speed improvement comes not from the format but from serving images at the size they are actually displayed. A photo shown 800 pixels wide on your page does not need to be a 4,000-pixel original; that is roughly 25 times more data than necessary.
Use the Image Resizer to scale the image down to its display size first, then convert to WebP. This two-step habit often cuts file size by 80% or more before WebP's own savings are even applied. The rule of thumb: never upload an image larger than it will ever be shown.
After resizing, a further pass through the Image Compressor strips metadata and reduces quality by an amount the eye cannot perceive. WebP already compresses well, but starting from a clean, compressed source produces the smallest final file.
Use WebP for almost all website imagery: hero photos, product shots, blog thumbnails, illustrations, and icons. It is the sensible default for anything displayed in a browser.
The main exceptions are files headed somewhere other than the web. Some older email clients, a few print workflows, and certain document systems still expect JPG or PNG. In those cases, keep a JPG copy as a fallback and reserve WebP for the site itself. If you ever need to move an image back to a traditional format, a converter can go the other direction too.
Google uses page experience signals, including loading speed, as a ranking factor. Large images are one of the most common causes of slow pages, so reducing image weight is one of the highest-impact SEO improvements available to most site owners.
Converting to WebP improves the Largest Contentful Paint metric — how quickly the main content appears — which feeds directly into Core Web Vitals. Combined with resizing and lazy loading, WebP can move a page from a poor speed score to a good one, benefiting both rankings and the visitors who no longer wait for heavy images to appear.
Converting one image is easy; keeping an entire website's images optimised takes a small, repeatable routine. The good news is that the same three steps apply to every image, so once the habit is set it takes almost no thought.
Applied to every image before it goes live, this routine keeps page weight low without you ever having to think about individual file sizes. For sites with many images, it is the single most effective performance habit you can adopt, and it costs nothing but a few seconds per image.
The real-world impact depends on how image-heavy your pages are, but the gains are usually substantial. On a typical content page where images make up the bulk of the payload, switching from unoptimised JPGs to resized, compressed WebP can cut total page weight by half or more. That translates directly into faster load times, particularly on mobile connections where bandwidth is limited.
Faster loading has knock-on effects beyond raw speed. Visitors are far more likely to stay on a page that appears quickly, so bounce rates fall. Search engines factor loading speed into rankings through Core Web Vitals, so the same change that pleases visitors also helps visibility. Few optimisations offer this combination of easy implementation and broad benefit.
Beyond format and compression, modern sites gain speed by serving different image sizes to different devices — a phone does not need the same large image as a desktop monitor. This technique, called responsive images, means a visitor only downloads the size their screen actually requires.
In practice this is done by preparing an image at several widths — say 400, 800, and 1,600 pixels — and letting the browser choose. On a small phone the browser downloads the 400-pixel version; on a large screen it fetches the 1,600. Combined with WebP, this can dramatically cut the data mobile visitors download, which matters most on the slower connections where speed is felt keenly.
Preparing these sizes is simply resizing the same source image a few times, then converting each to WebP. It takes a few extra minutes per key image, but for the hero images and photos that dominate a page's weight, the payoff in mobile speed is significant. If that sounds like more effort than a project warrants, a single well-resized, compressed WebP at a sensible width is still a large improvement over an unoptimised original — responsive sizing is the refinement, not the foundation.