Absinthe is a high-alcohol spirit that contains the herb wormwood. There are many variations on the drink, differing in such things as color, louche, herbs used in production, and region of production. Before purchasing absinthe, it is helpful to familiarize oneself with the different varieties available.

In the 19th century, absinthe was classified by an increasing scale of quality and alcoholic strength: ordinaire, demi-fine, fine, supérieure, and Suisse. Though these classifications, particularly the last two which denote the highest quality, can still be found on absinthe bottles, they are not of much significance today. However, it is important to note that Suisse does not refer to the spirit's country of origin, but rather to its quality and production style. Traditionally, both supérieure and Suisse absinthes were naturally flavored and colored and distilled.

Today, absinthe is often classified according to the process of production, as either "distilled" or "mixed." Distillation is the traditional method of making absinthe and is considered to produce a superior product. Mixed absinthes are made by cold mixing coloring and flavoring elements into a high-proof alcohol. Though many modern absinthes are made this way, some connoisseurs do not consider mixed varieties to be true absinthe. One should keep in mind that the distinction between distilled and mixed is not the ultimate arbiter of quality, as other factors, such as the quality of ingredients, also have an effect on the final product.

The best known and most popular type of absinthe is called verte, the French word for "green." Verte absinthe traditionally gets its green color and distinctive flavor from herbs added after distillation, though some absinthes are artificially colored and still referred to as "verte." If the coloring step used to make verte absinthe is not employed, the result is known as blanche ("white") or la Bleu ("the blue"). La Bleu is simply an alternate term for blanche, particularly Swiss varieties, and not a blue-colored spirit. Rose or rouge absinthe uses hibiscus flowers after initial distillation to produce a red color; this variety is rare, and only one historical example has been attested.

Both blanche and verte absinthes are made most often in Switzerland, the first country to produce the spirit, and France. Both varieties louche, or become cloudy with the addition of water. Both are traditionally made with grande wormwood, green anise, and florence fennel, along with other herbs depending on the particular recipe.

Some varieties of absinthe are limited to particular regions. Absenta, produced in Spain, is made with alicante anise. It is sweeter than French varieties and has a characteristic citrus flavor. Bohemian-style absinth, made in the Czech Republic, does not contain anise, fennel, or other herbs used in traditional Swiss or French absinthe. It is typically made using the cold mixing method and is more bitter than other varieties.

Hausgemacht ("homemade") or clandestine absinthe is a bootleg, home-distilled variety, notably produced in Switzerland. Hausgemacht absinthes were first made during the Swiss prohibition of the liquor from 1910 to 2005. Blanche varieties were more popular, as they were easier to hide. Bootleg Swiss absinthes were the first to be referred to as "la Bleu."