For almost every white-light job in a UK home, COB is the better strip: one continuous line of light with no dots, CRI90+ as standard, and no need to hide individual chips behind a deep diffuser. SMD keeps two real advantages, colour-changing effects and pixel control, and this guide is honest about both.
ATOM LED's DC range is built on dot-free COB, from £9.85 per metre, every run custom cut to your measurements before dispatch from Telford. Single-colour COB carries up to a 7-year warranty; RGB COB is 5 years.
CRI90+ COB · 24V and 48V · custom cut to order · up to 7-year warranty · free UK delivery
- What is the actual difference between COB and SMD?
- Which looks better on the wall?
- Is COB brighter, and does it cost more to run?
- Which should you fit in each room?
- How do they compare to cut and install?
- What about dimming, drivers and colour control?
- What do they cost, and which lasts longer?
- So which should you choose?
Quick decision summary
- White light anywhere it will be seen, reflected or diffused: COB.
- Colour-changing scenes or RGBW: SMD chips still do the mixing; our RGBW COB strip gets you both.
- Chasing and pixel effects: addressable COB or SMD pixel strip.
- Tightest budget on a hidden run: basic SMD tape, eyes open about CRI and warranty.
What is the actual difference between COB and SMD?
Construction. SMD mounts individual LED packages along the circuit board, typically 60 to 120 per metre, each one a visible point of light. COB mounts hundreds of tiny chips directly on the board and covers them edge to edge with a phosphor layer, so the whole strip glows as one continuous line.
The names say it: SMD is surface-mounted device, COB is chip-on-board. Our 24V COB packs 480 chips per metre under that phosphor; a typical SMD2835 strip carries 120 packages in the same length. Everything else in this comparison, the dots, the heat behaviour, the diffuser question, follows from that one difference in construction.
Which looks better on the wall?
COB, anywhere the light or its reflection is visible. SMD's separate chips read as a row of dots on gloss tiles, polished stone, glass shelves and curved coves. COB has no dots to hide, and at CRI90+ across our range it renders food, skin and paint colours accurately where most SMD tape sits at CRI70–80.
The dot problem is worst exactly where strip gets fitted: under cabinets above a gloss splashback, around a mirror, along a shelf edge. An opal diffuser softens SMD dots but costs 20–30% of the output and still shows scalloping at close range.
CRI is the quieter difference. At CRI90+ a tomato looks red and skin looks healthy; CRI70 tape pushes everything slightly grey. If a room is worth lighting, it is worth lighting at 90 or better.
Is COB brighter, and does it cost more to run?
Brightness is decided by watts per metre, not by chip type: our 14.4W/m COB delivers around 1,100 lumens per metre, and a 14.4W/m SMD strip lands in the same range. Efficiency is close enough that neither wins on the electricity bill; what differs is how evenly that light leaves the strip.
SMD concentrates each watt at a point, which is why bare SMD glares. COB spreads the same watts along the whole line, so it reads softer at identical output. Run 3 metres of 14.4W/m strip for 4 hours an evening and you use about 63 units of electricity a year, either way. Heat behaves the same: COB spreads it along the board, SMD stacks it at each chip, which is one reason cheap dense SMD tape ages fastest at its hottest points.
Which should you fit in each room?
Kitchens and bathrooms are COB rooms: reflective surfaces, close viewing and food or skin under the light. Living spaces that want colour scenes justify RGBW. Outdoors, the housing matters more than the chip, so choose by IP rating first: IP67 or better for anything properly exposed to weather.
- Under kitchen cabinets: 24V single-colour COB at 3000K or 4000K in a diffused profile. Our under-cabinet installation guide covers positioning and wiring.
- Bathroom mirrors: COB both sides of the glass, IP65 where spray can reach, CRI90+ for skin.
- Ceiling coves and curves: COB stays a clean line where SMD dots telegraph through.
- Outdoor runs: outdoor-rated COB; IP65 is splash resistance, not a UK winter outdoors.
How do they compare to cut and install?
Both cut at marked points with ordinary scissors: every 25–50mm on most COB, every 50–100mm on most SMD, so COB usually lands closer to the length you actually need. Fitting is identical, a clean dry surface or an aluminium profile, and the profile earns its keep with either strip.
Two honest notes. Cutting an IP65 strip on site breaks the seal at the cut, which is why we would rather cut, seal and terminate it for you. And one line in our range, the Free Cut 24V COB, cuts at any point along its length rather than at marks; the rest of the range, like all LED strip, cuts at its marked intervals. Send us your cutting list and every run arrives finished: this is the made-to-measure COB range we build most kitchens from.
What about dimming, drivers and colour control?
Identical rules, because dimming happens at the driver, not the chip. Single-colour strip of either type dims cleanly from a trailing-edge dimmable driver. RGB and RGBW strip must run on a non-dimmable constant-voltage driver with the controller doing the dimming; a dimmable driver on colour strip flickers and fails early.
Size the driver the same way for both: metres times watts per metre, plus 20% headroom. On long runs, 24V holds a single feed to about 10 metres and our 24V single-colour COB is rated to 20 metres; moving to 48V COB roughly halves voltage drop and stretches a single feed to 30 metres. Pair a trailing-edge dimmable driver with single colour, or a plain 24V driver and controller with colour-changing strip.
What do they cost, and which lasts longer?
The price gap has closed. Our dot-free 24V COB starts at £9.85 per metre with single-colour warranties up to 7 years; RGB COB carries 5 years. Marketplace SMD tape is cheaper on the day and usually CRI70–80 with a 1–2 year warranty, which is how a £5 reel becomes the most expensive strip you ever fit twice.
Lifespan comes down to heat. Chips driven hard in a hot spot age fastest, which punishes dense cheap SMD; COB's spread of hundreds of lightly driven chips runs cooler for the same output. Either type lasts longest in an aluminium profile from our LED strip profiles range, which sinks heat as well as straightening the line.
So which should you choose?
Choose COB for every white-light installation you will actually look at: kitchens, bathrooms, shelves, coves, wardrobes. Choose SMD-based strip when the job is colour, chasing effects or pixel control. If you are unsure, the room usually answers: reflective surfaces and close viewing mean COB.
We cut every order to your measurements before it ships, whichever you choose. Send your lengths and we will confirm the strip, size the driver and quote the runs.
Frequently asked questions
Is COB brighter than SMD?
- No, watts per metre decide brightness. COB looks softer because the same output leaves a continuous line instead of concentrated points.
Can I use COB strip without a profile?
- Yes. COB has no dots to diffuse, so bare mounting looks clean on matt surfaces.
- A profile still helps: it sinks heat, holds the strip straight and tidies gloss reflections.
Can I dim COB with a standard wall dimmer?
- Not directly. Dim single-colour COB through a trailing-edge dimmable driver; the wall dimmer controls the driver, never the strip.
Does COB work with RGB controllers?
- RGB and RGBW COB does, on a non-dimmable constant-voltage driver with the controller handling colour and dimming.
Which is better under kitchen cabinets?
- COB. The strip reflects in the worktop and splashback, and a continuous line survives that reflection where SMD dots do not.
Do COB strips use more electricity?
- No. At the same watts per metre the consumption is the same; efficiency differences between the two are marginal.
Why buy your LED strip from ATOM LED?
Bespoke, made-to-order lighting is what we do: every run is custom cut to your project's measurements and sealed before dispatch from Telford, so you fit a finished piece rather than a reel. The DC range is dot-free CRI90+ COB at 24V and 48V, single-colour warranties run up to 7 years, and free UK delivery covers 97% of products. Unsure which strip your project needs? Call 01952 370028 or email operations@atomled.co.uk, Monday to Friday, 9am to 5pm, and we will size it with you.