kallisto

kallisto is a program for near-optimal quantification of transcript abundances from RNA-Seq data, or more generally of target sequences using high-throughput sequencing reads. It is based on the idea of using pseudoalignment to quickly determine reads and targets’ compatibility, with no need for alignment.

According to benchmarks done on a Mac desktop computer, kallisto can quantify 30 million human bulk RNA-seq reads in less than 3 minutes with just the read sequences and a transcriptome index, that in itself can take more than 10 minutes to build. And since it uses pseudoalignment, it is robust to errors in the reads and preserves the key information needed for quantification. This makes kallisto not only fast but highly accurate as well. In many benchmarks, it even greatly outperforms existing tools.