A web-based graphical user interface application that allows browsing and analyzing immune repertoire sequencing (RepSeq) data. VDJviz can be used to visualize results of MITCR, MIGEC, MIXCR and MIGMAP RepSeq processing software as well as popular IMGT/HighV-QUEST and ImmunoSEQ Analyzer services. VDJviz can be installed and used as a local server. Alternatively you can use an online demo version which currently has an upload limit of 25 datasets each having size at most 10000 clonotypes.