A small songbird, greenish above, white below, with black-bordered white supercilium and thin white wingbars. Larger and more contrastingly marked than Yellow-browed Warbler, which has weaker wingbars and a generally stouter appearance. Not as elongate-looking as Arctic Warbler, with a shorter-billed profile and a more extensive white supercilium that reaches the base of the upper bill (Arctic's brow stops well short of the bill). Extremely similar to Greenish Warbler: Two-barred tends to be more brightly colored above than Greenish and has two wingbars instead of one. Song a series of quick trills and squeaks, lacking the two introductory notes of Greenish; call a flat series of three notes, similar to Greenish.