What does bitwise mean?
"Bitwise" is a technical adjective used in computing to describe operations that act directly on the individual bits—the elementary 0s and 1s—of a binary value, rather than on the number as a whole. Common bitwise operators include AND, OR, XOR, NOT, and shifts, which manipulate patterns of bits to perform tasks such as setting flags, masking data, packing multiple values into one integer, or accelerating arithmetic. For example, a programmer might write code that compares two numbers bitwise to determine where their binary representations differ. The word also serves adverbially, as in "the two values are combined bitwise," indicating that each corresponding pair of bits is processed independently. Confined almost entirely to programming, hardware documentation, and computer science education, "bitwise" carries a connotation of low-level efficiency and precision: bitwise tricks are prized for being extremely fast. Though obscure outside technical circles, it is indispensable vocabulary for anyone learning how computers represent and transform information at its most fundamental level.
(Computing) Involving or operating on the individual bits of a binary value.
"A bitwise XOR of the two integers reveals which bits differ."
Almost always used attributively, preceding a noun such as "operator," "operation," or "shift."
(Computing) In a way that acts on or considers data at the level of individual bits.
"The two bitmasks are compared bitwise during validation."
Every image you've ever viewed was decoded thanks to bitwise operations flipping millions of tiny 1s and 0s behind the scenes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bitwise
The word "bitwise" is a transparent compound of "bit," short for "binary digit"—a term coined by statistician John Tukey and popularized by Claude Shannon in his landmark 1948 work on information theory—and the Old English adverbial suffix "-wise," meaning "in the manner of." It therefore literally means "in the manner of bits," arising naturally alongside modern digital computing in the mid-twentieth century. The suffix "-wise" itself descends from Old English "-wīse," related to "wise" in its older sense of manner or way, connecting it etymologically to formations such as "likewise" and "clockwise."
How bitwise is actually used
Strictly a technical term confined to computer science and programming contexts; it would sound out of place in general conversation. It functions attributively before nouns ("bitwise operator") and predicatively after verbs like "compare" or "combine." The adverbial sense is usually expressed by simply placing it after the verb rather than adding "-ly."
Easily confused with bitwise
"Bitwise" refers to manipulation of individual bits (0s and 1s), while operations described as byte-wise act on whole groups of eight bits at a time.