It is one of the most diverse genera in the family and is composed of small birds that inhabit dense undergrowth across tropical and subtropical habitats in the Neotropical region.

Most species show the long graduated tail with pointy feathers that is typical of spinetails.

They are also characterized by constructing large domed nests with stick, including a long entrance tube.

Some species can be difficult to distinguish from one another on the basis of their plumage, but can be told apart by their vocalizations, which can be quite distinctive.

[1] The genus Synallaxis was introduced in 1818 by the French ornithologist Louis Pierre Vieillot.