Chicks don't have visible masculine or feminine features, the way we think of them.
Or maybe bearded chicks sorta do... but even the females have beards, so it's no help!
Our experts "vent sex" baby chicks. Vent sexing means they look at tiny differences in the birds' cloaca. (That's a fancy word for "bird butt.") You would think there would just be two shapes, one for male and one for female, but there are actually 15 different shapes in chickens. It's definitely hard to tell the difference, even for experts with many years of experience. It's considered more of an art than a science.
Feather sexing is another way to tell the difference between males and females. In certain breeds, the primary wing feathers are shorter on newly-hatched males than they are on females of the same breed. But this only works in some strains of some breeds--and only in newly hatched baby chicks. It will not normally work at home--not unless you have the right breed, the right strain, and you hatched them yourself, anyway.
While sexing baby chicks with any method is not one hundred percent accurate (we achieve about 95% sexing accuracy), we guarantee 100% accuracy, from a cost standpoint. This means that if you have received a male chick when you have paid for a female, My Pet Chicken will refund you for that bird. See our guarantees. My Pet Chicken is also the only place in the country that offers sexed bantams.
If you're trying to tell the difference at home or with chicks you've hatched, you may not have any luck for many weeks. Early signs can be a larger, redder comb and wattles, but some pullets mature faster than others and some roosters take longer to mature, so usually it is a waiting game! In some breeds, spurs are common in both sexes (bantams in particular), and in others only the rooster will have spurs. However, females will have bumps where the spurs would grow, and at a young age it is not possible to use these to tell the difference. In short, unless you have an autosexing breed, it's near impossible to tell until your bird produces a full-on crow (at about 5 months) and develops longer, pointier feathers on their tail and around their neck (at about three months)! Even more confusingly, hens will sometimes crow. See below for more information about that.
Finally, if you've grown to love a "she" that turned out to be a "he," and you can't keep him for noise reasons, consider our No-Crow Rooster Collar! It makes a rooster as quiet as a hen.