In my code I'm trying to show a UIWebView as a page is loading, and then, when it's done, capture an image from the web view to cache and display later (so I don't have to reload and render the web page). I have something along the lines of: CGContextRef context = CGBitmapContextCreate(…); [[webView layer] renderInContext:context]; CGImageRef imageRef = CGBitmapContextCreateImage(context); UIImage *image = [UIImage imageWithCGImage:imageRef]; The problem I'm running into is that, due to UIWebView's tiling, sometimes only half of the page is rendered to the context by the time I capture the image. Is there a way to detect or block on UIWebView's background rendering thread so that I can get the image only after all of the rendering has finished?