we build an app where we use responsive HTML5-Articles inside.
On older iOS Devices (iPad2 and iPad4 for Example) the performance is so bad that it is not really usable. It takes for example up to 15 seconds from opening a downloaded Article until it is fully rendered.
We have got a lot of Pictures and Videos inside but inside the OS-Browser it works much better.
Is there someone who has got the same Issues or any idea how to optimize the performance (especially on older Devices)?
The OS control used to display web content on iOS is a different rendering technology than the OS browser, and has different performance characteristics. In particular it is slower on older devices, such as the iPad 2.
Given your description my guess is your image size is driving the performance issues. Take a look at how big in pixels your images are and aggressively re-compress them. I've had success scaling images to 50% of the size I think I need, and then saving them as JPEG at a 7 (or even 5) quality level in Photoshop.
As for the videos, make sure you're using the <video> tag with a link to the video hosted somewhere for streaming purposes.
you are absolutely right but we made some more tests yesterday without these larger .jpeg-Files and the effect was the same (then the whole article was around 6mb). Even when we reduced half of images inside this article, the performance was really bad …
I looked at the first article on the first browse page (article-33). The total download size is 11.1MB, of which 7.9MB is JPEG images. It’s also over 249 files. Many of the images are small, which is great, but you still have some on the larger side.
Can you add email@example.com<mailto:firstname.lastname@example.org> to the project with Preflight permission? I wouldn’t mind taking a quick peek at the content to see if I can identify anything else that might be content-related driving the performance you’re seeing.