Why is there a delay when displaying content in a UIWebView?

Question

iOS

There is a WebView located on one of the screens in the storyboard, in this WebView, when you go to the page, a local html page is loaded (via NSURLRequest). In some cases (always at the first launch after installing the application and at startup after a long period of inactivity of the application), there is a delay before the html page is displayed. That is, at first a white screen is shown, and only after 1-2 seconds the content is displayed. After that, all pages in the application are displayed quickly, without delay.
The html page itself is nothing special, a few kilobytes of text and several styles connected via external css.
What could be the reason for this delay? How to eliminate?

Answer 1

I came across this moment - it turned out that webview initializes some internal caches and styles at startup. Therefore, the first download takes ~1sec.
I made an alpha animation when loading the page so that the user is not annoyed by the window that suddenly appears.