Motivation: Sanger sequencing remains the reference method for sequence variant detection, especially in a clinical setting. However, chromatogram interpretation often requires manual inspection and in some cases considerable expertise. Additionally, variant reporting and nomenclature is typically left to the user, which can lead to inconsistencies. Results: We introduce GLASS, a tool built to assist with the assessment of gene variations in Sanger sequencing data. Critically, it provides a standardized variant output as recommended by the Human Genome Variation Society. Availability: The program is freely available online at http://bat.infspire.org/genomepd/glass/.