Why do graphics look blurry after uploaded to twitter and facebook?

[Jon]

After I upload graphics or use graphics for my twitter wallpaper, they come out very blurry. What format should I be using?

Thanks.

[david b]

They have image processing scripts which probably reduce the image size, which infact reduces quality.

[Eva]

I think its because the images you upload are too small, so Twitter blow them up to fit your screen.

It is best to use a twitter background with a 1600px width and 1200px height

Hope this helps!