How to reduce image size for the web
Images are the most common cause of slow pages. The good news: you can cut their size several times over with almost no quality loss.
Why it matters
Heavy images slow loading, hurt Core Web Vitals and search rankings, and cost mobile users data. Images are often the biggest part of a page's weight.
The main trick — switch to WebP
At comparable quality, WebP weighs noticeably less than PNG and JPG. Converting PNG → WebP or JPG → WebP usually cuts size by 25–50% with no visible difference. It's the fastest way to lighten images.
- PNG → WebP — for graphics, screenshots and images with transparency.
- JPG → WebP — for photographs.
- PNG → JPG — if WebP doesn't fit and you don't need transparency: JPG is lighter than PNG.
Also
Before converting, resize the image to its real display size — loading a 4000 px photo shown at 800 px is pointless. 'Right size + WebP' gives the maximum effect.