Since the first sequencing of the human genome more than 20 years ago, the study of human genomes has relied almost exclusively on a single reference genome to which others are compared to identify genetic variations. Scientists have long recognized that a single reference genome cannot represent human diversity and that using it introduces a pervasive bias into these studies. Now, they finally have a practical alternative. Researchers have introduced a new tool, called Giraffe, that can efficiently map new genome sequences to a ‘pangenome’ representing many diverse human genome sequences.