Enter a nonnegative integer and choose the base it is written in to see the same value in eight bases. Conversion is exact at any size, and digits outside the selected base are reported instead of skipped.
Runs locally in your browserType a number, choose the base it is written in, and the page prints that same value in eight bases: binary, octal, decimal, hexadecimal, base 32, base 58, base 62 and base 64. The conversion runs in this page — nothing is uploaded.
Values are read and written exactly. A 64-bit identifier, a long hexadecimal string or a wide decimal is converted with integer arithmetic, so the last digit is not rounded away and the result does not depend on how large the number is.
The buttons and the Other base list cover every base from 2 to 62 plus base 64. Bases up to 36 use 0-9 followed by a-z, so base 2 accepts 0 and 1 and base 16 accepts 0-9 and a-f. From base 37 the sequence continues with A-Z; base 26 and base 52 use letters only.
Four bases keep their published alphabets instead of that order: base 32 is Crockford (0-9 and A-Z without I, L, O and U), base 58 is the Bitcoin alphabet (1-9, then A-Z without O and I, then a-z without l), base 62 is 0-9 then a-z then A-Z, and base 64 is the RFC 4648 alphabet A-Z a-z 0-9 + /. Base 63 is not offered.
Every character is checked against the alphabet of the base you selected. A character that is not a digit of that base is named, the digits the base accepts are listed, and the result fields stay empty: 12 is refused in base 2 instead of being read as 1 or 3, and 12ab is refused in base 10.
Letters ignore case where the alphabet does not mix the two, so base 16 accepts ff, FF and fF. They are case-sensitive where both cases are digits of their own, as in base 58, 62 and 64. Leading zeros are allowed, and spaces around the number are ignored. Only digits of the selected base are accepted, so decimal points, digit separators and a leading sign are refused: -255 and 12.5 have no place here. The + and / of the base 64 alphabet are digits, not signs.
Numbers are integers without a size limit: 18446744073709551615, the largest 64-bit value, prints as ffffffffffffffff in base 16, and a 23-digit decimal keeps every digit. Fractions, negative numbers and text are refused rather than truncated.
The results are plain digit strings with no prefix and no padding: no 0x or 0b, base 16 in lower case, and bases 32, 58, 62 and 64 in their own alphabets. This page converts numbers, not text: it does not produce the byte-oriented Base64 or Base58 encoding of a string.