One Format Change Can Cut Your File Size in Half or More
One of the easiest, highest-impact ways to improve website performance is switching image formats. JPEG and PNG are old and universally compatible, but their compression efficiency lags behind newer formats. WebP, developed by Google, typically cuts file size by 30-50% versus JPEG or PNG at similar visual quality, and AVIF uses even newer compression techniques that often beat WebP's savings rate.
This calculator takes your original image size, image count, and conversion type — JPEG→WebP, PNG→WebP, JPEG→AVIF, or PNG→AVIF — and estimates total savings and savings rate. On sites with many images, these savings compound and can meaningfully impact overall page load time and server bandwidth. Converting 100 PNG images at 500KB each to AVIF, for example, saves dozens of megabytes instantly.
In practice, you also need to factor in browser compatibility. WebP is supported by nearly all modern browsers, but AVIF isn't supported on some older ones, so it's safer to serve the original format as a fallback using a picture tag. Image CDNs or build tool plugins can automate this conversion and fallback handling for you.
FAQ
AVIF usually achieves a higher savings rate, but WebP is the safer choice if you need to support older browsers.
WebP and AVIF often maintain the same visual quality while using more efficient compression algorithms to reduce size.
Image CDNs, build tool plugins (webpack, vite, etc.), or online conversion tools can all handle this conversion easily.