White-winged tapaculos are small and drab birds, being mostly gray in color with brownish, barred upperparts and tails, and a distinctive patch of white on the wing.

[2][1] The species was described in 2020 as Scytalopus krabbei by the American ornithologist Tom Schulenberg and his colleagues on the basis of an adult male specimen collected from the Alto Mayo Protection Forest in 2002.

[5] The specific epithet honors the Danish ornithologist Niels Krabbe for his contributions to the study of Scytalopus tapaculos, including the description of seven new species of the genus.

It has no subspecies;[6] populations from Huánuco and Amazonas show a divergence of 4.3–4.4% in their ND2 sequence, but there are no known accompanying differences in their appearance and vocalizations.

Phylogenetic reconstructions based on mitochondrial DNA have found it to be sister (most closely related) to the Ancash tapaculo.

They are mostly gray in color, with brownish, barred upperparts and tails; their most distinctive feature is the small patch of white on the wing, which is unique among tapaculos in their genus.

The lower back, rump, and uppertail coverts are dark brown, the last of which has two or three oblique blackish stripes near the end.

It can be told apart from the neblina tapaculo by its larger size, thinner bill, the absence of a whitish supercilium, and dusky (instead of brownish) tail.

It is distinguished from the trilling tapaculo by its shorter tail and tarsi, darker gray coloration, and barred flanks.

The species also gives a "scold" call, a unique one second-long trill comprising 9–12 notes delivered at a maximum pitch of 3200–3900 hertz.

[2][1] Despite its relatively distinctive appearance, the white-winged tapaculo's cryptic nature means that its vocalizations are typically the best way to identify the species.

[2][1] The white-winged tapaculo is known only from north-central Peru, where it has been recorded from five localities in three regions of the Andes: Cordillera Colán in Amazonas, Cerro Patricia in San Martín, and in Huánuco, in Bosque Unchog and between Zapatagocha and Huaylaspampa.

It is a restricted-range species and only occurs in mountain ranges within the North-east Peruvian cordilleras Endemic Bird Area, which is relatively unthreatened.