css - what is the actual resolution of an iphone screen -

i'm developing webpages viewd on iphone. exact resolutions on iphone tested following lines of code.

    pagewidth = $j(document).innerwidth();     alert(pagewidth); 

according http://www.iphoneresolution.com/ iphone 5 has 640px width,

but when execute code following alert.

this image simulator, same on iphone

can please tell me so?.

thanks

screen.width give width of device's screen.

you'll want note device's resolution not correspond resolution webpage displays in.

see http://www.mydevice.io/devices/