Is this pure breed australorp?

[Australorpdabest]

25 days old

 

[JedJackson]

If you got him from a hatchery or good breeder, then probably. If you got him from a backyard breeder with lots of different kinds of chickens, then probably not. The feet look white, not yellow, which is good sign of the chick being an Australorp rather than a Jersey Giant.