ClustalW2 is a general purpose DNA or protein multiple sequence alignment program for three or more sequences. For the alignment of two sequences please instead use our pairwise sequence alignment tools.
The ClustalW2 services have been retired. To access similar services, please visit the Multiple Sequence Alignment tools page. For protein alignments we recommend Clustal Omega. For DNA alignments we recommend trying MUSCLE or MAFFT. If you have any questions/concerns please contact us via the feedback link above.