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.
Why we do not score any open-coil mattresses#
Every sprung mattress in our catalogue uses pocket springs, and that is deliberate. In twenty years on the shop floor, open-coil mattresses were the ones that came back: sagging in the middle, transferring every movement, and wearing out in five years. These are the sprung mattresses we do recommend.
| Model | Type | Depth | Feel | Support | Comfort | Price (double) | Why it is here |
|---|---|---|---|---|---|---|---|
| LuxeTherm Hybrid | Hybrid | 28cm | Medium | 8.0 | 8.0 | £337 (sale) | Pocket springs from £337 |
| Tencel 1000 | Pocket spring | 28cm | Soft | 7.8 | 8.3 | £339 (sale) | 1,000 pocket springs, soft feel |
| Luxe Velour Hybrid | Hybrid | 28cm | Medium | 8.2 | 8.4 | £399 | The default pocket-sprung hybrid |
| Pocket Reflex 1000 | Pocket spring | 28cm | Medium | 8.2 | 8.0 | £399 | Springs and reflex foam; bouncy and responsive |
| Imperial 2000 Pocket Spring | Pocket spring | 29cm | Firm | 8.7 | 7.8 | £449 | 2,000 springs; the traditional pocket-sprung feel |
| LuxeErgo 3400 Hybrid | Hybrid | 31cm | Firm | 9.0 | 9.0 | £464 (sale) | 3,400 springs in two layers; the best sprung support we score |
Prices are for a double at the time of writing (September 2026), using the sale price where the brand runs a permanent one. Full scores are on each review page. We may earn a commission if you buy through our links, at no extra cost to you; it never affects a score.
The price gap that once justified open coil has closed: pocket springs now start at £337 for a double with a trial. If a mattress under £300 is sprung, it is almost certainly open coil, and a dense foam mattress such as the Superior Cashmere will outlast it.
Frequently asked questions#
Are pocket springs better than open coil?#
For almost every buyer, yes. Pocket springs move independently, so they contour to the body, isolate movement between partners and wear evenly. Open coils are wired together, so they move as a sheet, transmit motion, and sag toward the middle as they age.
How many pocket springs should a mattress have?#
1,000 or more in a king is the sensible minimum for adult use; 1,500–3,000 is typical of good hybrids. Beyond about 3,000 the count is largely marketing unless the springs are in multiple layers or micro-spring comfort layers.
Is open coil ever the right choice?#
For a guest bed used a few nights a year, a child's bed, or a budget under £200 where a firm, cheap sprung feel is wanted, an open-coil mattress is acceptable. For a main bed, a dense foam mattress at the same price is a better buy.
What is a Bonnell spring?#
The traditional hourglass-shaped open coil, wired to its neighbours with helical wire. It is what most people mean by 'open coil' or 'continuous coil'. Cheap, durable in a crude sense, and poor at contouring or isolating movement.
Related reading#
- Pocket springs vs memory foam – springs against foam
- What is a hybrid mattress? – pocket springs plus a comfort layer
- Mattress types explained – all the types
- Best budget mattress UK – what to buy instead of cheap open coil
- Pocket spring collection – every sprung mattress we score
