keithcurtis said: Lag reports are hard to diagnose (You've hit hardware accelleration, which is the 800 pound gorilla of DL lag). Some folks seem to get lag no matter what, others never seem to run into it. I rarely encounter any significant lag, for instance. How complex is the map? Things to look out for: Excessive light sources. Do you have more than a few dozen? NPCs with vision. Although this is less of a lag issue than a display issue. Lots of NPCs with nightvision can make a dark room look bright, for instance. Excessive points in DL lines. Avoid using the freehand tool if possible. The lines it generates are needlessly complex and can affect display. Theoretically, a lot of freehand lines could affect performance as well. Also huge maps might be problematic (in excess of 60x60 grid squares, though this can vary widely based on other parameters--there is no strong rule of thumb here.) Try running in a private browsing window, to rule out interference from extensions, cookies or cached data. Make sure you are using a supported browser (Chrome, Firefox). As a pure test, you can also try temporarily switching one for the other, to see if there might be a browser setting at play. Keith, along these lines, is there a post anywhere here with "UDL best practices"?