How do I know if my chainsaw chain just needs sharpening or needs to be replaced?

A dull chain throws sawdust instead of clean chips, requires leaning into the cut, and leaves a rough, burned surface—that’s fixable with a five-minute sharpening. A chain that needs replacement has visibly worn drive links, cutters filed too short, broken teeth, or worn tie straps. The easiest test: if it still cuts poorly after sharpening, it’s done. Don’t run a worn-out chain—it can burn up the bar or break at speed.