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The Best Image Format for Websites in 2026

Which image format should your website use? AVIF, WebP, JPG, PNG or SVG, with real file size tests and a simple setup that works in every browser.

· 2 min read · ImgKoi Team

Images are usually the heaviest part of a web page. Picking the right format is one of the easiest ways to make a site faster, and faster sites rank and convert better.

The short answer

  • Photos: AVIF or WebP, with JPG as a fallback.
  • Logos and icons: SVG.
  • Screenshots and graphics with text: WebP (lossless or high quality), or PNG.
  • Animations: animated WebP or a short video instead of GIF.

Why modern formats win

We saved the same photo with our converter at default settings:

Format1600 × 1200 photo1200 × 800 screenshot
AVIF56 KB9 KB
WebP92 KB17 KB
JPG175 KB38 KB
PNG1.81 MB65 KB

AVIF was about 68% smaller than JPG for the photo, and WebP about 47% smaller, at the same quality setting.

Browser support

WebP works in every current browser. AVIF works in current Chrome, Edge, Firefox and Safari (version 16 and later). If you need to support very old browsers, serve a fallback with the HTML picture element: the browser picks the first format it understands.

A simple setup

  1. Resize images to the largest size they're displayed at. A 4000-pixel photo shown 800 pixels wide wastes most of its bytes. Use Resize Image.
  2. Convert photos to WebP or AVIF: JPG to WebP, JPG to AVIF.
  3. Convert transparent PNGs to WebP: PNG to WebP.
  4. Use SVG for logos and icons.
  5. Set width and height on every image so the page doesn't jump while loading.
  6. Lazy-load images below the fold with loading="lazy".

When JPG and PNG still make sense

  • Email newsletters: some email apps don't show WebP or AVIF reliably.
  • Images people will download and reuse.
  • Open Graph images for social sharing: JPG or PNG is the safest.

For head-to-head details, see AVIF vs WebP and WebP vs JPG.