Which image format should you choose?

For a website: WebP

WebP is 25 to 35% lighter than JPG at the same quality and keeps transparency like PNG. It’s supported by every current browser. Lighter pages load faster, which matters directly for SEO.

To go even further: AVIF

AVIF is about 20% lighter than WebP, but slower to make (several seconds per image) and a little less universal. A good choice for an online shop with many photos.

For print, email or older software: JPG

JPG remains the most universally accepted format. No transparency: a transparent background turns white when converting.

For a logo or a screenshot: PNG or SVG

PNG loses no detail and keeps transparency, but is heavy on a photo. For a logo or icon, SVG (vector) is even better: it scales infinitely without loss.