I did reuse cells by registering and dequeuing. Here is a short example code that reproduces the issue. When scrolling through, memory usage climbs up to ~230mb. When font size is changed, it also changes the max memory usage. Memory usage also depends on how many cells are visible at a time but controlling that value, font size is directly correlated with memory usage. Keyboard extension has 70mb so using the same font size as system keyboard won't work for keyboard extension since memory usage goes up to 230mb. My keyboard app has been released for over 6 years and was fine but with recent iOS update, something changed and caused the increase in memory usage for the UILabels.