Ketchup (ⁱ/ˈkɛtʃəp/ or ⁱ/ˈkɛtʃʌp/), or catsup, is a table sauce. Traditionally, different recipes featured ketchup made of mushrooms, oysters, mussels, walnuts, or other foods,^[1][2] but in modern times the term without modification usually refers to tomato ketchup, often called tomato sauce, or, occasionally, red sauce. It is a sweet and tangy sauce, typically made fromtomatoes, a sweetener, vinegar, and assorted seasonings and spices. Seasonings vary by recipe, but commonly includeonions, allspice, cloves, cinnamon, garlic, and sometimes celery.^[3] Heinz tomato ketchup, which contains 23.7g sugar and 3.1g of salt per 100g, is the market leader, with an 82% market share in the UK.^[4]

Tomato ketchup is often used as a condiment with various dishes that are usually served hot, including chips/fries,hamburgers, sandwiches, hot dogs, french toast, eggs, and grilled or fried meat. Ketchup is sometimes used as a basis or ingredient for other sauces and dressings. Ketchup is also used as a flavoring for things such as crisps/potato chips, and this variety of crisps/chips is one of the most-popular flavors in Canada. This flavor of potato chip has also been offered in the U.S. as recently as September 2014.^[5]