The BLAST Ring Image Generator (BRIG) is a little Java program for visualizing prokaryote genomes. BRIG is a cross-platform (Windows/Mac/Unix) application that can display circular comparisons between a large number of genomes, with a focus on handling draft genome assembly data.

The application is freely available at:

Click here to see a wonderful gallery of all the figures others have made with BRIG. If you have any questions or comments, post them on BRIG’s SourceForge page.


  • Images show similarity between a central reference sequence and other sequences as concentric rings.
  • BRIG will perform all BLAST comparisons and file parsing automatically via a simple GUI.
  • Contig boundaries and read coverage can be displayed for draft genomes; customized graphs and annotations can be displayed.
  • Using a user-defined set of genes as input, BRIG can display gene presence, absence, truncation or sequence variation in a set of complete genomes, draft genomes or even raw, unassembled sequence data.
  • BRIG also accepts SAM-formatted read-mapping files enabling genomic regions present in unassembled sequence data from multiple samples to be compared simultaneously

Please cite the BRIG paper if BRIG is used to generate figures for publications:

With BRIG anyone can make pictures like these in a matter of minutes. BRIG is available here under the GPL3 licence. I’ve written the program to use CGView for the image rendering and BLAST for the genome comparisons. The source code is available on GitHub.

BRIG example output image of a simulated draft E. coli O157:H7 genome.
The figure show BLAST comparisons of 28 other published (E. coli and
Salmonella) genomes against the simulated draft

BRIG image showing the presence, absence and variation of individual
genes from the E. coli O157:H7 str. Sakai Locus of Enterocyte Effacement
(LEE) in related pathogens and E. coli K12, a non-pathogenic strain of
E. coli known to lack the LEE