The HPLC Gradient is a high performance liquid chromatography. They are used for reversed-phase separations. They are convenient and robust in its nature and deals with compounds whose polarity vary widely. General accepted problems with isocratic separations are poor resolution of early eluted peaks, increased peak width and inability having a broad range of hydrophobicity taking longer time. The Gradient HPLC help to overcome issues, by providing better peak shape and the ability to elute analytes in a reasonable time frame. They involves the on-line mixing of solvents to achieve a steady increase in the organic solvent. Further, it also serves to increase the elution strength of the eluent over time.