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Best Cot Mattresses: Firm, Safe and Correctly Fitted

A cot mattress is a fit-and-care decision, not a comfort competition. The useful shortlist is firm, flat, clean, dry and made for the exact cot, with no promise that a product reduces sleep risk.

Quick recommendation

The John Lewis pocket-sprung option is the familiar all-round comparison, Silentnight keeps the price lower and IKEA KINDERÄTT makes sense when its dimensions match the cot exactly.

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The shortlist

Our Top Picks

Browse all guides →
John Lewis Pocket Sprung Cot Mattress illustrative product image

Illustrative image

Editorial roundup pick

£80indicative price
★ 4.4 Our rating0–4 yearsBest for Parents wanting a firm, flat cot mattress with a familiar retailer route.

Still worth it after 12 months? MOSTLY

The useful test is whether it keeps earning a place in the family routine after the first few weeks.

A mattress decision is mostly about exact fit, firmness, flatness and a clean, dry history—not a comfort claim or a safer-sleep guarantee.

Good to know

  • + Firm and flat brief
  • + Clear fit check

Watch for

  • − Exact cot fit matters
  • − Price varies
Parent hassle: 2/5
Value: 4/5See this pick

Recommendation → see the retailer → you decide.

Silentnight Safe Nights Cot Mattress illustrative product image

Illustrative image

Editorial roundup pick

£55indicative price
★ 4.2 Our rating0–4 yearsBest for Families looking for a lower-cost cot mattress starting point.

Still worth it after 12 months? MOSTLY

The useful test is whether it keeps earning a place in the family routine after the first few weeks.

A practical option when the dimensions, firmness and current care guidance match the exact cot.

Good to know

  • + Accessible price
  • + Clear cot brief

Watch for

  • − Fit needs measuring
  • − Care instructions matter
Parent hassle: 2/5
Value: 4/5See this pick

Recommendation → see the retailer → you decide.

IKEA KINDERÄTT Cot Mattress illustrative product image

Illustrative image

Editorial roundup pick

£70indicative price
★ 4.3 Our rating0–4 yearsBest for IKEA cot owners who want the matching mattress dimensions.

Still worth it after 12 months? MOSTLY

The useful test is whether it keeps earning a place in the family routine after the first few weeks.

A sensible route when the mattress and cot are a confirmed match; measure rather than assuming a brand match is enough.

Good to know

  • + Useful dimensions
  • + Simple care

Watch for

  • − Only fits some cots
  • − Cover care matters
Parent hassle: 2/5
Value: 5/5See this pick

Recommendation → see the retailer → you decide.

Safety

Safety notes

The sleep space stays simple

  • Use a firm, flat mattress that fits the cot exactly, with no gaps. Keep the sleep space clear: nothing else belongs in it unless current safer-sleep guidance says otherwise.
  • Do not use a second-hand mattress unless it is completely clean, dry and its history is known. State plainly: no mattress reduces the risk of SIDS.
  • Follow safer-sleep guidance from the Lullaby Trust and NHS, and check the exact cot and mattress instructions.

At a glance

How they compare

Read product reviews →
ProductOur ratingAgeParent hassleValueBest for
John Lewis Pocket Sprung Cot Mattress4.40–4 years2/5StrongParents wanting a firm, flat cot mattress with a familiar retailer route.
Silentnight Safe Nights Cot Mattress4.20–4 years2/5StrongFamilies looking for a lower-cost cot mattress starting point.
IKEA KINDERÄTT Cot Mattress4.30–4 years2/5IKEA cot owners who want the matching mattress dimensions.

Buying advice

What to look for.

These are editorial starting points, not a certification system. Check the maker’s instructions, the real retailer price and the child’s individual fit before buying.

01

Choose firm and flat, with an exact fit and no gaps around the edge.

02

Keep nothing else in the sleep space. No mattress reduces the risk of SIDS.

03

Do not use a second-hand mattress unless it is completely clean, dry and its history is known.

04

Check dimensions, firmness, cover care and whether the mattress is approved for the exact cot.

05

Signpost current safer-sleep guidance from the Lullaby Trust and NHS rather than treating a product label as certification.

Our method

How We Tested

We compared the practical details that decide whether a product earns space: setup, fit, storage, cleaning, repeat use, parent effort and value. This is editorial guidance, not a record of laboratory testing or a safety certification.

Note: product prices, imagery and retailer availability can change. Check the live listing and current manufacturer guidance before buying.

Our Verdict

The short answer

The John Lewis pocket-sprung option is the familiar all-round comparison, Silentnight keeps the price lower and IKEA KINDERÄTT makes sense when its dimensions match the cot exactly.

Questions parents ask

FAQ

Read reviewsRead the cot mobiles guideBrowse baby gear
How should a cot mattress fit?+

It should be firm, flat and an exact fit, with no gaps. Check the mattress and cot dimensions against the current manufacturer instructions.

Can a mattress reduce the risk of SIDS?+

No mattress reduces the risk of SIDS. Keep the sleep space clear and follow current Lullaby Trust and NHS safer-sleep guidance.

Can I use a second-hand cot mattress?+

Only if it is completely clean, dry and its history is known. When that cannot be established, choose a new, correctly fitting mattress.

The useful list

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