Duplo-style bricks have been copied by plenty of other brands over the years, and after a few years of toddler play it's easy for a Mega Bloks set or an ELC toy to end up in the same bin. Here's how to tell what's genuine before you sell.
Check the underside
The most reliable check: turn the piece over. Genuine LEGO Duplo bricks are almost always stamped "LEGO" or "DUPLO" somewhere on the underside of the studs. Clone brands typically either have no marking at all, or stamp their own brand name instead.
Feel and finish
Genuine Duplo has a distinctive weight and a slightly glossy, consistent finish. Clone bricks are often a touch lighter, with a duller or slightly different-coloured plastic — not always obvious on its own, but a useful second check alongside the stamp.
Why the difference matters
We only buy genuine LEGO Duplo, priced by weight. Clone bricks, other toys, and non-Duplo LEGO all fall outside that, so anything that isn't genuine Duplo gets set aside during checking and isn't included in your offer.
A quick sort saves time
Before you weigh and post, a five-minute check through the bin — flipping a sample of pieces to check for the LEGO/DUPLO stamp — is enough to catch most clone bricks and keep your offer accurate.