Can hydrolyze glycol chitin and chitin oligosaccharides (e.g. N-acetylglucosamine) (GlcNAc)4, (GlcNAc)5 and (GlcNAc)6 (PubMed:21390509, PubMed:22936594). Hydrolyzes N-acetylglucosamine oligomers producing dimers from the non-reducing end of the substrates (PubMed:21390509). Random endo-hydrolysis of N-acetyl-beta-D-glucosaminide (1->4)-beta-linkages in chitin and chitodextrins. Hydrolysis of N,N'-diacetylchitobiose from the non-reducing end of chitin and chitodextrins. Glycan degradation; chitin degradation. Induced by jasmonic acid (JA), abscisic acid (ABA) and salt (NaCl). Belongs to the glycosyl hydrolase 18 family. Chitinase class V subfamily.