Caffeine is a naturally occurring alkaloid widely consumed through tea and coffee, known for its psychoactive effects on the human brain. The concentration of caffeine varies significantly depending on the type, brand, and processing of tea and coffee products. This research paper presents a comparative chemical analysis of caffeine levels in selected commercial brands of tea and coffee using UV-visible spectrophotometry. This study reveals significant brand-to-brand variation in caffeine concentration, indicating that commercial processing and formulation strongly influence the final caffeine content of tea and coffee products. Five popular brands were analyzed to determine variations in caffeine concentration. Caffeine showed a sharp absorption maximum at 273 nm in the UV region, which was selected for quantitative estimation. The calibration curve (2–20 µg/mL) followed Beer–Lamberts law with excellent linearity (R² ≈ 0.999). Coffee samples exhibited significantly higher absorbance and caffeine content (≈55–110 mg/cup) compared to tea samples (≈12–35 mg/cup). The method demonstrated good precision, accuracy (98–102% recovery), and low detection limits, confirming that UV–visible spectrophotometry is a simple, reliable, and cost-effective technique for caffeine analysis in commercial beverages.