Sort sequences by decreasing length. The output file is specified by the -fastaout or -fastqout option. The -minseqlength (-maxseqlength) option can be used to specify a minimum (maximum) length to keep.
The -relabel prefix option can be used to generate sequential labels for the sorted sequences (requires v6.0.235 or later). The output label is prefixN where N=1, 2, 3 etc. If -sizeout is used, a size annotation will be appended to the sequential label.
The -topn N option specifies that no more than N sequences should be output.
The -minseqlength and -minseqlength options specify a minimum and maximum length.
Example
usearch -sortbylength seqs.fasta -fastaout seqs_sorted.fasta -minseqlength 64