The decision in one sentence
Use AVIF for photos with a WebP fallback, PNG (or WebP lossless) for graphics with sharp text, and SVG for anything that's actually a vector — logos, icons, simple illustrations.
Photos: AVIF first, WebP second, JPG fallback
For any natural photograph on the web, AVIF gives you the smallest file at the highest visual quality. Pair it with a WebP fallback for the long tail of older browsers, and a JPG as a final safety net. Modern HTML's <picture> element handles this automatically — Chrome, Firefox, and Safari 16+ pick AVIF; older Safari picks WebP; everything else falls back to JPG.
Screenshots, UI, text-heavy graphics: PNG or WebP lossless
When the image contains text, sharp edges, or large flat color regions, lossy compression introduces visible ringing artifacts around the edges. Use PNG for guaranteed pixel-perfect rendering, or WebP in lossless mode (quality 100) for the same fidelity at a smaller file size. AVIF lossless works too but is slower to encode and the savings versus WebP lossless are often marginal for graphics.
Logos, icons, simple illustrations: SVG
If the artwork is geometric — a logo, an icon, a simple chart — SVG wins on every axis: tiny file size, infinite scalability, themeable with CSS, and crisp at any pixel density. Run your SVGs through Converter.Plus's /svg-optimizer to strip editor metadata before deploying.
Why image format matters for SEO
Google's Core Web Vitals — particularly Largest Contentful Paint (LCP) — heavily weight how quickly your hero image renders. Switching from a 400 KB JPG hero to a 120 KB AVIF version directly improves LCP and, with it, your Page Experience signal. For content-heavy sites the cumulative bandwidth and render-time savings translate to faster pages, lower bounce rates, and better SERP placement.
How to migrate your existing library
Drop a folder of JPGs into Converter.Plus's /jpg-to-avif and /jpg-to-webp tools to generate optimised variants in batch. For an automated pipeline, use a Sharp- or libvips-based build step that outputs both AVIF and WebP for every JPG/PNG source — then use the <picture> element to let the browser pick the best one.
Frequently asked questions
Will switching to AVIF break older browsers?
Not if you use the <picture> element with a JPG fallback. Browsers that don't understand AVIF skip past it and load the fallback automatically.
Is GIF still relevant?
Almost never. For animations, WebP and AVIF both produce dramatically smaller files at higher quality. For static images, JPG or PNG are always better choices.