COB vs SMD LED Strip: Which One Fits the Project?
COB and SMD strip compared on dot visibility, cost per lumen, efficacy, cut length and heat. A decision table for specifying the right construction.
HFY Applications Engineering · Published September 8, 2026 · 3 min read
COB strip removes the dot pattern by bonding dies under a continuous phosphor layer; SMD strip places packaged LEDs at a fixed pitch and costs 20–30% less per metre at the same flux. COB is the correct choice when the strip is visible or sits behind a shallow diffuser. SMD wins when the strip is hidden behind 3 mm or thicker acrylic, or when cost per lumen is the deciding factor.
Key points
- The decision is optical: what sits between the strip and the eye.
- At matched flux and CRI, COB costs 20–30% more per metre than SMD.
- SMD offers more flexibility in CCT and CRI because packages can be mixed on one FPC.
- Neither construction changes the heat problem — both lose life at the same rate in a sealed profile.
The comparison in one table
| Criterion | COB | SMD |
|---|---|---|
| Dot visibility | None at 100 mm | Visible below ~12 mm pitch |
| Cost per metre, matched flux | 100% | 70–80% |
| Efficacy, CRI 80, 4000 K | 130–160 lm/W | 140–190 lm/W |
| Maximum CRI available | 95 | 90, 95 on some packages |
| Cut length | 25–50 mm | 25 mm (3 LEDs on 24 V) |
| Repair at component level | Not practical | Possible |
| Sealed profile heat | Same | Same |
Two rows deserve attention because they are usually misquoted.
Cost per lumen, not cost per metre
A comparison by the metre flatters COB or SMD depending on wattage. The honest comparison is cost per 1,000 lumens at the same CRI and CCT. A 12 W/m 480 chips/m COB strip at CRI 90 produces roughly 1,150 lm/m, and a 14.4 W/m 2835 SMD strip at CRI 90 produces roughly 1,750 lm/m. Normalising both to 1,000 lumens, the COB option costs 18–25% more — narrower than the 30% figure quoted on price lists, but still real.
If the project is 2,000 m of cove lighting behind a diffuser, that difference is the entire budget conversation.
Where COB genuinely wins
- Shallow profiles. A 12 mm deep aluminium profile with a 1.5 mm diffuser cannot average an 8.3 mm dot pitch. COB solves this without changing the fixture.
- Mirror and glass backlighting. Reflection doubles the dot pattern, and clients notice it immediately.
- Retail shelving at eye level. Customers stand 400 mm from the shelf, which is inside the distance where SMD dots resolve.
- Tight cut tolerance. A 25 mm cut length on 480 chips/m means less waste per run than 50 mm segments on a low-density SMD strip.
Where SMD genuinely wins
- Behind 3 mm or thicker diffusers, where both look identical.
- High efficacy targets. 190 lm/W is achievable on 2835 at CRI 80 and is not yet matched by COB at the same price.
- Mixed CCT builds. Two packages on one FPC give a tunable white strip with a simple two-channel driver.
- Repair and maintenance contracts, where component-level replacement matters for a facility team.
The test that settles it
Put both strips in the actual profile, behind the actual diffuser, and look at them from the actual viewing distance. Every argument above collapses into that one check, and it takes ten minutes. We send 500 mm samples of both for exactly this purpose — see COB LED strip and SMD LED strip for the stocked configurations.
The related question of how hot either construction runs inside a closed profile is covered in heat management for LED strip, and it affects life far more than the choice between COB and SMD.
This article describes general manufacturing practice for machined and fabricated components. It is not a substitute for a drawing-specific engineering review — tolerances, material selection and process capability depend on the individual part.