Redstarts are very similar in size to the Robin but have a longer tail that constantly quivers up and down. Their tail and rump are bright orange/red with the central tail feathers being brown. They have a black bill and legs.
In summer the male has blue/grey upperparts, a black face and throat with a white forehead and eyebrow with the breast and flanks being orange.
Females have grey/brown upperparts and orange/buff underparts a whitish belly and a pale eye-ring.
In winter, both sexes are browner and have less black.