The page is the BLAST (basic local alignment search tool) module of the R-loopAtlas. The module enables users of the database to compare a query sequence with a library or database of sequences, and identify library sequences that resemble the query sequence above a certain threshold. At present, it contains the genomes and CDS sequences of 254 species. In addition, there also contains R-loop sequence of Arabidopsis thaliana and Oryza sativa Japonica.