How to repair a zipper on a pair of jeans using ZlideOn
A fly zipper that slides open on its own or refuses to close is nearly always a worn slider, not a ruined pair of jeans. Swapping it takes a couple of minutes and no sewing — which matters, because the fly is one of the fiddliest seams to unpick and restitch.
Get the right ZlideOn for your jeans
First things first! Check the number stamped on the back of your old slider (denim flies are usually 4 or 5), or measure the width of the zipper teeth, and pick the ZlideOn that matches.
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Carefully snap off the broken slider
Grip the old slider with a pair of pliers and snap it off the top of the fly, above the metal stopper. Denim is stiff, so fold the fly flat first to give yourself a clear line of pull.
Fully open your ZlideOn
Hold the ZlideOn between your fingers and open it up completely, so the two halves are ready to sit around the zipper chain.
Click it onto the zipper
Place the open ZlideOn over the zipper teeth and press both sides firmly together until you hear it click shut. Run it up and down the fly a few times to bed the teeth in — your jeans are repaired.
Better to see it in action?
The whole repair takes less than a minute. Watch it done from start to finish.
Watch the ZlideOn repair video
Important things to remember
ZlideOn replaces the slider — not the zipper chain itself. Before you start, check the teeth and the tape stitched into the fly: if teeth are missing or the tape has pulled away from the denim, the fly needs restitching rather than a new slider. Far more often the slider has simply worn loose, which is exactly what causes a fly to creep open on its own.
Getting the size right matters. Check the number stamped on the back of your old slider or measure the width of the zipper teeth before ordering. Jeans flies are usually size 4 or 5 in metal. If you're unsure, a multipack covers the most common sizes and is the safe choice.
A jeans fly is a closed-end zipper, so the ZlideOn goes on from the top, past the stopper at the waistband end. If the zipper skips or won't hold after the first few pulls, don't force it: open the slider, check that both rows of teeth are seated fully inside, and press it shut again.
Why repair your jeans instead of buying a new pair?
Denim only gets better with age, and a broken fly is a poor reason to give up a pair that finally fits properly. Replacing the slider with ZlideOn takes minutes, costs a fraction of a new pair, and needs no sewing, tools, or tailor. Made in Europe from durable zinc and steel, a ZlideOn slider will outlast the denim around it.
Repair, don't replace. A single pair of jeans takes thousands of litres of water to produce. Keeping yours in service is one of the simplest, most effective sustainable choices you can make — and with ZlideOn, it's also one of the easiest.