How open-coil springs work#

Open-coil (also called continuous coil or Bonnell coil) mattresses use a single piece of wire formed into a network of connected coils. Because all the springs are interconnected, movement on one side of the mattress is transmitted to the other. This is the traditional spring mattress design used in the UK for over a century.

Open-coil advantages: Lower manufacturing cost, making them cheaper. Very durable wire construction. Lighter weight than pocket-sprung alternatives.

Open-coil disadvantages: High motion transfer — movement on one side wakes the other sleeper. Less precise contouring to body shape. Less independent support across the sleep surface.

How pocket springs work#

Pocket-sprung mattresses use individually wrapped springs (each in its own fabric "pocket"). Because each spring moves independently, one side of the mattress can respond to pressure without affecting the other side. A queen-size pocket-sprung mattress might contain 1,000–3,000 individually pocketed springs.

Pocket-spring advantages: Dramatically reduced motion transfer — each spring responds independently. Better body contouring — springs compress where your body creates pressure, providing zoned support. Better for couples with different weights or sleep positions.

Pocket-spring disadvantages: Higher manufacturing cost. More complex construction means more potential failure points over very long periods (though quality pocket springs last well).

Spring count: does it matter?#

Spring count is often used as a marketing metric, but it requires context. A mattress with 1,500 quality pocket springs will outperform one with 3,000 cheap springs. The quality of the steel, the coil design and the fabric pockets matter more than the raw count. That said, a higher spring count in a quality mattress generally means finer contouring and better motion isolation.

Who should choose which?#

Open-coil is acceptable for: Spare rooms, children's mattresses (they move around enough that motion transfer is irrelevant), budget applications where longevity isn't critical, single sleepers who aren't sharing a bed.

Pocket springs are better for: Main bedrooms, couples sharing a bed, anyone who values quality sleep, back or side sleepers who need precise support. For a primary mattress that will be used for 8–10+ years, pocket springs are always worth the additional investment.

The verdict#

For any adult buying a main bedroom mattress, pocket springs are the clear choice. Open-coil mattresses have a place in spare rooms and budget applications, but for regular nightly use, the motion-isolation and support advantages of pocket springs are too significant to ignore. All the hybrid mattresses on our comparison page use pocket springs.