Endo-hyaluronidase that degrades hyaluronan to smaller oligosaccharide fragments. Also has chondroitin sulfate hydrolase activity, The best substrate being the galactosaminidic linkage in the sequence of a trisulfated tetrasaccharide. . This is the function of Ensembl gene identifier ENSG00000106302 (HYAL4, hyaluronidase 4).