Proteoform Suite is a software program that performs intact-mass analysis and quantification of proteoforms in mass spectrometry MS1-only data. In a typical top-down analysis, more proteoforms are observed in the MS1 spectra than identified by MS2; Proteoform Suite increases the number of proteoform identifications in top-down analyses by identifying proteoforms by accurate intact mass. Proteoform Suite also constructs and automates the visualization of proteoform families by grouping together related proteoforms based on mass differences and liquid chromatography elution time. Proteoform Suite can integrate both bottom-up and top-down data to maximize the number of proteoform identifications.