This toad from the Kelabit Highlands was described by Masui et al. (2020). The authors diagnosed Ansonia kelabitensis as "a small-sized Ansonia, males 23–25 mm,females 25–29 mm; head not much depressed; tympanumvisible externally; tips of outer fingers spatulate; tip of firstfinger not reaching disk of second when fingers areadpressed; fifth toe with two phalanges free of web in bothsexes; keratinized mandibular spinose tubercles and black-ish brown nuptial pad present in males; no interorbital ridges;tarsal ridge rarely recognizable; no light band from eye toarm." For more taxonomic information see ASW. 

The type locality is New Dam, Bario, Miri Division, Sarawak (03°45′N, 115°26′E, 1150 m a.s.l.). 

Ansonia kelabitensis can be found at night along mountain streams (width < 3 m). The toads perch on leaves of low vegetation along the bank or several meters from a small stream. According to Matsui et al. (2020), tadpoles were found in the stream in mid August. The presence of many calling males in mid August and early January also indicate to the authors that these months could be breeding season for the species.

The authors also provide photographs of the tadpoles. They grow up to almost 29 mm in total length and are similar to other stream adapted tadpoles of, for example, A. kanak or A. hanitschi. Differentiating characters still need to be established.