Shrink your images without uploading them

Almost never bigger than 2,000 pixels wide, and usually 1,200 is plenty. A photo straight off a modern phone is 4,000 pixels and several megabytes, and the browser throws most of it away after making your visitor download all of it.

No. Everything happens in your browser using the canvas built into it. The file never leaves your computer, which is also why this works on a photo you would not want to hand to a stranger.

WebP for almost everything on a website now: it is smaller than both and supported everywhere that matters. Keep PNG only when you need a transparent background and WebP is not an option, and avoid PNG for photographs, which is a common and expensive mistake.

Often the difference between a four second load and a one second load. On a site whose score sits in the thirties, compressing images is usually worth more than every other fix put together, and it costs nothing.