The diverse biochemical profiles of microalgae, particularly Dunaliella salina and Spirulina platensis, make them essential to biotechnological fields. These microalgae stand out for their high biomass production and capacity to store important materials including proteins, lipids, polysaccharides, and carotenoids in a variety of environmental settings. This work provides a comprehensive evaluation that compares these two popular microalgal species, closely examining important characteristics such organic matter, pigments, carotenoids, carbohydrates, and proteins, along with moisture content, ash content, and ash-free dry weight. The investigation validated the exceptional ability of Dunaliella salina to store protein and β-carotene, indicating its potential use in nutraceutical applications. On the other hand, Spirulina platensis showed increased protein content, which strengthened its standing as a helpful dietary supplement. Spirulina's somewhat higher carbohydrate content suggests that the biofuel industry may find use for it. By identifying each microalga's distinct characteristics in more detail, proximate analysis provided important new information about their potential applications in biotechnology. This thorough characterisation clarifies their inherent benefits notwithstanding the impact of environmental factors and strain selection on their biochemical makeup. By highlighting these qualities, the study advocates for the sustainable use of Dunaliella salina and Spirulina platensis as answers in the rapidly evolving field of biotechnology, and it lays out a path for their advanced usage in a variety of industries, including food, cosmetics, pharmaceuticals, and biofuels.