The black-capped pygmy tyrant is a tiny short-tailed bird, 6.5 cm long, and weighing 5.2 g. The crown is black, shading to dark grey on the rest of the head, and contrasting with the white “spectacles”. The rest of the upperparts are olive-green.
The black-capped pygmy tyrant is a small bird characterized by its short tail, size (6.5 cm), and weight (5.2 grams). It has a distinctive black crown that transitions to dark grey on the rest of its head, contrasting with its white "spectacles". Its upper body is olive green.