High-Performance Liquid Chromatography (HPLC) is a high-resolution technique for separation and quantitation of range of small molecules, biomolecules, and peptides. Ultra-high performance (UHPLC) systems are capable of increased pressure and are designed for increased resolution and performance. Platform availability ranges from all-in-one to modular and scalable systems. Metrics to consider include: pressure capacity, flow rate control, method development options, and compatibility. Columns and consumables are always a cost consideration, as well as maintenance, service, and repair. When purchasing, consider whether a new system is backward compatible with existing methods and if software is available for used models.