The chemical name of vanillin is 4-hydroxy-3-methoxybenzaldehyde, also known as methyl protocatechualdehyde or vanillin. It is an important broad-spectrum high-end fragrance and one of the largest produced fragrances in the world as of 2019. It has a sweet bean and powder aroma and can be used as a fixative, coordinator, and flavoring agent. It is widely used in industries such as food, beverages, cosmetics, daily chemicals, and pharmaceuticals. The usage proportion in downstream industries is about 50% for food additives, 20% for pharmaceutical intermediates, 20% for feed additives, and about 10% for other purposes.

Vanillin is currently one of the most widely used food flavoring agents in the world, known as the "king of food spices". It is mainly used as a flavoring agent in the food industry and is applied in cakes, ice cream, soft drinks, chocolate, baked goods, and alcoholic beverages. Its dosage in pastries and biscuits is 0.01% to 0.04%, in candies it is 0.02% to 0.08%, and the highest dosage in baked goods is 220mg · kg-1. The highest dosage in chocolate is 970mg · kg-1. It can also be used as a food preservative additive in various foods and seasonings; In the cosmetics industry, it can be used as a flavoring agent in perfume and face cream; In the daily chemical industry, it can be used to modify the aroma of daily chemical products; In the chemical industry, as defoamers, vulcanizing agents, and chemical precursors; It can also be applied for analysis and detection, such as testing amino compounds and certain acids; In the pharmaceutical industry, as an odor blocking agent. Due to its antibacterial properties, vanillin can be used as a pharmaceutical intermediate in the pharmaceutical industry, including in the treatment of skin diseases. Vanillin has certain antioxidant properties and cancer prevention effects, and can participate in signal transmission between bacterial cells. In the future, these potential application areas will promote rapid growth in the demand for vanillin in the market. As of 2019, the annual consumption of vanillin in the global market is around 20000 tons.