Keep Your Images Small
Small images download faster, and the faster your page downloads the more likely people will stay. A good maximum size for images is 10K.
Resize Images with Graphics Software Not the Browser
When you use the
height attributes to resize your images, you increase the amount of time it takes the browser to render the page. The browser has to spend time determining how the display the image, and this is time that many people will simply leave your site.
Always include descriptive alt text
Alt text using the
alt attribute is required for valid HTML. But it also makes your pages more accessible. Alt text displays when the image hasn’t downloaded yet, or if there is a problem with the download.