The input file contains 3 alignments of 15 different species, if we sum the length of them, we obtain 253.

You should now be on the output page, with two expandable output results. The first one, the concatentor.out is the expected result. It should contain our 3 alignments together pasted one after the other, keeping the order of the input file. The second output file, is a log file, it contains information about how the process has run. As you can imagine many unpredictable errors reading the imput file can occur, depending on how you put the alignment together in the same file. So it is really important to check in this log file the number of alignments detected by ConcatenAl and the number of species.