Reasons for not using IFrame?

Question

are there any reasons not to use iframes at all? I currently use it to load a page from a different server (a sign up page - part of a distributed application) to provide a seamless experience. Is using iframes considered bad practice or is its use OK?

Answer 1

With HTML 5 you'll be able to use the cross document messaging API to send messages from window to window, but for now the iFrame is the most viable alternative to any sort of AJAX that requires styling and scripting to load with the data.

If you're looking to just use text data in the iFrame, use AJAX instead. If you want external CSS or JavaScript to work in a protected environment, want styling to start from scratch, or need to access cross domain documents, use the iFrame.

Cons are that the accessibility of iFrames generally sucks, although you can prevent this by making sure that you proceed the iFrame with a notice of external content for screenreaders. Also check the HTML specifications for other ways to make the iFrame more accessible. Other than that and the obvious limitations scripting wise, the iFrame is a great tool is used responsibly and sparsely.

One last note, piling a page full of iFrames is definitely not a good idea, as remember that for each loaded iFrame, a DOM is created, HTML requests are made and document wrappers are instantiated, eating memory and bandwidth in the process. Keep iFrame's to a minimum on the page, and you'll avoid misuing a powerful tool in the HTML aresenal.