CRISPR/Cas system undoubtedly holds great potential for genome editing. Target site cleavage by CRISPR technology requires a protospacer adjacent motif (PAM) immediately downstream or upstream of the protospacer element to which the sgRNA binds. However, Cas9 from different types of bacteria or variant recognizes different PAM sequences. To meet the needs of different CRISPR system with specific and efficient sgRNA design, CRISPR-offinder was developed.