If the slider has moved past misaligned teeth, gently pull it down to the base and zip up again. If realignment doesn’t work, replace the slider with a new one. Fully unzip the zipper.

Unfortunately, you can’t really fix this problem permanently unless you completely replace the zipper. That said, there are ...

Over time, these sliders start to loosen and gape making them less effective at fixing the teeth in place. While you can take your garment to a tailor to replace the entire zipper, there is a ...