32 символға негізделген мәтіндік кодтау жүйесі

Binary to text encoding scheme using 32 symbols
Base32 is an encoding method based on the base 32 numeral system. It uses an alphabet of 32 digits, each of which represents a different combination of 5 bits (25). Since base32 is not very widely adopted, the question of notation—which characters to use to represent the 32 digits—is not as settled as in the case of more well known numeral systems (such as hexadecimal), though RFCs and unofficial and de facto standards exist. One way to represent Base32 numbers in human readable form is using digits 0–9 followed by the twenty two upper case letters A–V. However, many other variations are used in different contexts. Historically, Baudot code could be considered a modified (stateful) base32 code. This article focuses on the use of Base32 for representing byte strings rather than unsigned integer numbers, similar to the way Base64 works.

The October 2006 proposed Internet standard documents base16, base32 and base64 encodings. It includes two schemes for base32, but recommends one over the other. It further recommends that regardless of precedent, only the alphabet it defines in its section 6 actually be called base32, and that the other similar alphabet in its section 7 instead be called base32hex. Agreement with those recommendations is not universal. Care needs to be taken when using systems that are called base32, as those systems could be base32 per RFC 4648 §6, or per §7 (possibly disregarding that RFC's deprecation of the simpler name for the latter), or they could be yet another encoding variant, see further below.

Changing the Base32 alphabet, all alternative standards have similar combinations of alphanumeric symbols.

An earlier form of base 32 notation was used by programmers working on the Electrologica X1 to represent machine addresses. The "digits" were represented as decimal numbers from 0 to 31. For example, 12 16 would represent the machine address 400 (= 12 × 32 + 16).

Before NVRAM became universal, several video games for Nintendo platforms used base 31 numbers for passwords. These systems omit vowels (except Y) to prevent the game from accidentally giving a profane password. Thus, the characters are generally some minor variation of the following set: 0–9, B, C, D, F, G, H, J, K, L, M, N, P, Q, R, S, T, V, W, X, Y, Z, and some punctuation marks. Games known to use such a system include Mario Is Missing!, Mario's Time Machine, Tetris Blast, and The Lord of the Rings (Super NES).

Base32 programs are suitable for encoding arbitrary byte data using a restricted set of symbols that can both be conveniently used by humans and processed by computers. Base32 implementations use a symbol set made up of at least 32 different characters (sometimes a 33rd for padding), as well as an algorithm for encoding arbitrary sequences of 8 bit bytes into the Base32 alphabet. Because more than one 5 bit Base32 symbol is needed to represent each 8 bit input byte, it also specifies requirements on the allowed lengths of Base32 strings (which must be multiples of 40 bits; hence padding). The closely related Base64 system, in contrast, uses a set of 64 symbols. Base32 implementations in C/C++, Perl, Java, JavaScript Python, Go and Ruby are available.