HPLC vs UPLC: what is the difference?

High-Performance Liquid Chromatography (HPLC) and Ultra-Performance/Ultra-High-Pressure Liquid Chromatography (UPLC/UHPLC) separate compounds in a liquid sample by pumping it through a packed column.

The core difference

The defining variable is particle size of the column packing. Conventional HPLC uses 3–5 µm particles and operates up to ~400 bar. UPLC uses sub-2 µm particles and requires systems rated to 1000+ bar.

• Resolution: smaller particles give sharper peaks and better separation.
• Speed: UPLC runs are often 3–10× faster for an equivalent separation.
• Solvent use: UPLC consumes far less mobile phase per run.
• Cost: UPLC instruments and columns cost more; HPLC remains the workhorse for routine QC.

When to choose which

Choose HPLC for established methods, robustness and lower cost of ownership. Choose UPLC when throughput, sensitivity or very complex matrices justify the higher pressure tolerance and price. Many labs run both, validating methods on HPLC and high-throughput screening on UPLC.