The BLAST Ring Image Generator (BRIG) is a user-friendly, cross-platform desktop application designed for visualizing and comparing prokaryote genomes. It generates circular images that display similarity between a central reference sequence and other sequences as concentric rings, with BLAST matches colored according to a sliding scale of percentage identity. BRIG supports draft genome data, including read coverage, assembly breakpoints, and collapsed repeats, and can handle large numbers of genomes without arbitrary limits. The software is accessible to users with no computational expertise, as it automates file parsing and BLAST comparisons. BRIG is freely available for all operating systems and offers a range of customization options through its graphical user interface. It is particularly useful for analyzing draft genome sequences and visualizing the presence, absence, or variation of specific gene sets within multiple genomes.The BLAST Ring Image Generator (BRIG) is a user-friendly, cross-platform desktop application designed for visualizing and comparing prokaryote genomes. It generates circular images that display similarity between a central reference sequence and other sequences as concentric rings, with BLAST matches colored according to a sliding scale of percentage identity. BRIG supports draft genome data, including read coverage, assembly breakpoints, and collapsed repeats, and can handle large numbers of genomes without arbitrary limits. The software is accessible to users with no computational expertise, as it automates file parsing and BLAST comparisons. BRIG is freely available for all operating systems and offers a range of customization options through its graphical user interface. It is particularly useful for analyzing draft genome sequences and visualizing the presence, absence, or variation of specific gene sets within multiple genomes.