We have gotten lots of reports that it can take very long for MediaViewer to display (unblur) the images (some people mentioned 20-30 second waiting times); our tests and metrics, on the other hand, show a one second median loading time (slightly faster than the old method of opening the file page). We need to find out under what conditions does the application become so slow; if you experience something like that, or know other people who have experienced it, please help us collect more information.
Ideally, we would like to know the following:
- how long did it take for the image to load? (time spent between clicking on a thumbnail, and the blurry image becoming sharp)
- can you reproduce the slow loading time with other images? (Use images from a different wiki page, so that they are not preloaded)
- can you reproduce the slow loading time with same image, after refreshing the page with a clear cache (Ctrl-F5 on most browsers)?
- what OS/browser do you use?
- what kind of machine do you use? (Especially if it is an older/slower one, pointers on CPU speed and memory would be helpful.)
- what kind of internet connection do you use, what bandwidth does it have?
If you are comfortable with using the network tab on the web console of your browser (F12 on most browsers), and can look at it and tell us in detail which requests took up the majority of the loading time, that would be even more helpful.
- @From: Thanks for the report! The first time you open MediaViewer (after a cache clear or after not doing it for several weeks) is indeed somewhat slower since the JS files have to be downloaded. Normally this should be a small delay (the script is about 160K if your browser supports compression, which all modern browsers do; a typical image is going to be about the same size). But it's always possible something goes wrong on a specific browser or a specific connection; can you share more details about those? --Tgr (WMF) (talk) 07:26, 28 January 2016 (UTC)
For me, the black screen (!) persists for between 30 seconds and a minute. This seems to be platform-independent (tested: Android Chrome and OS X Firefox) until you try Firefox on Windows and find that a loading bar gets displayed and gets stuck at an estimated 5%. Ten minutes later, still stuck.
- @Samsara: loading bar getting stuck must be some sort of error (although normally MediaViewer captures the error and displays a nice error page). Do you see any error messages on the web console?
- The black screen is normally present while the application itself loads, and is afterwards replaced by a low-quality temporary image, but this depends on circumstances. Do you have a quick connection? Does this happen all the time, or just once in a while (maybe once every browsing session)? Does it change depending on which image you click on? Does it change depending on which page you are on? (Maybe a huge page which hundreds of images, such as a category page?) Does it change depending on which wiki you are on? Does the image appear immediately/quickly after the black screen goes away? --Tgr (WMF) (talk) 03:33, 30 November 2016 (UTC)