optimizeLegibility on Mobile Devices

In a comment on my post about optimizeLegibility, Marco Arment points out that there are significant, and even fatal, performance problems with this text-rendering mode on mobile devices. Marco Arment writes:

I did some testing with Instapaper to determine approximate optimizeLegibility performance limits. A 5,000-word article in Instapaper for iOS, for instance, will only use optimizeLegibility on devices with an A5-class or greater CPU. To avoid problems on older iOS devices, I wouldn’t recommend using optimizeLegibility blindly and unconditionally on any pages longer than about 1,000 words. And I wouldn’t recommend enabling it on Android at all.

So for now it seems like it’s a good idea to be conservative with the use of this property, using it sparingly and avoiding it altogether for older mobile devices. If in doubt, use it for headings only.

author picture Written by Dmitry Fadeyev
Published on November 15, 2012