BAli-Phy estimates multiple sequence alignments and evolutionary trees from unaligned DNA, amino acid, or codon sequences. BAli-Phy uses MCMC to estimate evolutionary trees, positive selection, and branch lengths while averaging over alternative alignments. BAli-Phy can display alignment ambiguity graphically in an alignment uncertainty (AU) plot.

BAli-Phy can also estimate phylogenies from a fixed alignment (like MrBayes and BEAST) using substitution models like GTR+gamma. BAli-Phy automatically estimates relative rates for each gene.