Alphanumerik

Alphanumerik is a term used to describe strings that consist of both alphabetic characters and numerals. It is commonly used to refer to alphanumeric data or to the set of characters that includes letters and digits, as distinct from purely alphabetic or numeric data. The form with a final "k" occurs in some languages as a direct translation or adaptation of the English "alphanumeric."

In computing, alphanumeric data are represented by character encodings such as ASCII or Unicode. A typical alphanumeric constraint limits input to the Latin letters A–Z (upper or lower case) and the digits 0–9, though some contexts permit additional characters such as underscores or hyphens. Alphanumeric strings are widely used for identifiers, usernames, product codes, serial numbers, and similar keys, where mixing letters and numbers helps expand the namespace and improve readability.

When used in security contexts, alphanumeric strings are often combined with punctuation to form robust passwords, balancing memorability with entropy. In databases and form validation, enforcing alphanumeric input can prevent certain types of injection or formatting errors while maintaining human readability.

Variants and spelling notes: the term is often written as alphanumeric in English; alphanumerik is a spelling variant found in some languages and technical communities. See also: alphanumeric character, password policy, SKU, barcode, and character encoding.