What does the alt attribute exactly make?

Question

What does the alt attribute exactly make in a img? I know that I can google it, but every tutorial which I find says that alt protides alternative text for images, that aren't loaded and when i try to do it, it doesn't show anything : http://jsfiddle.net/VGq5D/.

Answer 1

• Most browsers will display it when the image does not load (your example works when I try it in Firefox)
• Most browsers will display it when images are turned off
• Text browsers (such as Links and Lynx) will display it
• Screen readers will read it out
• Search engines may pay attention to it