Close-up of the gap between two mattresses pushed together

Bed Gap Filler: Two Very Different Problems

Some people search "bed gap filler" for the seam between two mattresses. Others mean the slot next to a headboard. Same words, two different fixes. Let's find yours.

Find Your Gap
Two different searches

Which gap are you trying to fix?

"Bed gap filler" gets used for two completely different problems. Here's how to tell them apart in ten seconds.

If two mattresses are pushed together and there's a seam or dip running down the middle, that's the gap this page covers. Keep reading below.

If the gap is between your mattress and a headboard or wall, that's a different problem with a different product. We don't sell one. Our sister page covers it honestly: headboard gap guide (Dutch page).

From here on, everything is about the gap between two mattresses, and closing it for good.

The problem

Why the gap between two mattresses keeps coming back

Two mattresses next to each other are never really joined. Nothing holds them together, so normal movement pulls them apart night after night.

You push them back at bedtime. By morning, the seam is back. Roll toward the middle and you feel it. Sit on the edge and one side dips lower than the other.

Close-up seam where two mattresses meet with a visible gap
The seam always finds its way back.
Two mattresses being pushed together by hand to close the gap
Push them together tonight. They'll drift apart again.
Why foam wedges fall short

A foam wedge fills the gap. It doesn't close it.

A foam wedge is the most common fix people try first. It's a triangle of foam that sits in the seam, covering the dip.

The problem is what it doesn't do. It isn't attached to either mattress. It just rests there, so the first time you move in your sleep, it can shift out of place.

Once it shifts, the bump comes back, and so does the gap underneath it. It's a cover-up, not a fix. Read more in Bedbinder vs mattress wedge.

The gap filler that actually connects your mattresses


Bedbinder Deluxe installed between two mattresses with no visible gap
Underneath, not on top

The Bedbinder Deluxe straps two mattresses into one

Instead of filling the gap, the Bedbinder Deluxe removes it. Straps wrap under both mattresses and pull them tight against each other.

Because it holds from underneath, it doesn't shift when you move. The mattresses stay connected, night after night.

Invisible under the sheets, fitted in under a minute, no tools required.

The difference

Mattress connector vs. foam gap filler

Bedbinder Deluxe (mattress connector) Foam wedge
Closes the gap for good Yes Temporarily
Stops mattresses from sliding apart Yes No
Stays in place overnight Yes Shifts loose
Feels like one mattress under the sheets Yes No, you feel a ridge
Works on twin beds, split setups and boxsprings Yes Inconsistent
Installation

Fitted in under a minute

No tools, no special skills. Here's the whole process.

1

Push together

Slide both mattresses against each other until they meet in the middle.

2

Lay the connector

Place the Bedbinder across the center, right where both mattresses meet.

3

Pull tight and buckle

Pull the straps through underneath and clip the buckles closed.

Done. Make the bed as usual. The gap stays closed, no matter how much you move at night.

FAQ

Frequently asked questions about bed gap fillers

What's the difference between a mattress gap filler and a headboard gap filler?

A mattress gap filler joins two mattresses pushed side by side, closing the seam between them. A headboard gap filler is a separate product that blocks the slot between a mattress and a headboard or wall. They solve different problems. The Bedbinder Deluxe is a mattress gap filler; we don't sell a headboard version.

What is the best gap filler for two mattresses pushed together?

A strap system that connects both mattresses from underneath, like the Bedbinder Deluxe, works better than a foam wedge. It pulls the mattresses together instead of just filling the space between them, so the gap can't reopen.

Why does a foam wedge stop working after a few weeks?

A foam wedge sits loose in the gap. It isn't attached to either mattress, so normal movement during sleep pushes it out of place. Once it shifts, the gap and the bump both come back.

Will a mattress connector stop the mattresses from sliding apart too?

Yes. Sliding and gapping have the same root cause: two separate mattresses that aren't attached to each other. The Bedbinder Deluxe straps both mattresses together, so they move as one unit instead of drifting apart.

Bedbinder Deluxe installed between two mattresses on a boxspring, no gap visible

Close the gap between your mattresses for good

Now that you know which gap you have, here's the fix. Order today, sleep gap-free tomorrow.

Order the Bedbinder Deluxe

30-night trial. Not happy? Full refund, no questions asked.