Not to be confused with canonization, declaring somebody as a saint.

Canonicalization is the process of converting data that has more than one possible representation into a "standard" canonical representation. This can be done to compare different representations for equivalence, to count the number of distinct data structures (e.g., in combinatorics), to improve the efficiency of various algorithms by eliminating repeated calculations, or to make it possible to impose a meaningful sorting order.

As an example, Wikipedia uses canonicalization in its processing of links between articles (see Wikipedia:Canonicalization). The first letter in the article name is capitalized, leading and trailing spaces are removed, and embedded whitespace is replaced by underscores. For example,

[[Egg_salad]]
[[egg salad]]
[[  egg_salad  ]]

all refer to the same article.

A more commonly used example is in boolean logic. It is theoretically possible (though not always feasible) to reduce any logic function to its conjunctive normal form, disjunctive normal form, or algebraic normal form.

See also: normal form.