Base64Deco“9” in Base64
The text “9” encodes to the 4-character Base64 string below. Everything on this page is derived the same way the homepage tool derives it: the text is converted to its UTF-8 bytes, those bytes are regrouped from 8-bit chunks into 6-bit chunks, and each 6-bit value is read off the standard alphabet.
Encoding result
The UTF-8 payload is 1 byte; the encoded output is 4 characters including padding, a growth factor of about ×4.00.
How the first bytes are encoded
Each group of three bytes becomes four output characters. Taking the first 1 byte of this text step by step:
| Bytes | 8-bit binary | 6-bit indices | Alphabet output |
|---|---|---|---|
0x39 | 001110 01 | 14 → 16 | OQ== |
The indices point into the 64-character alphabet ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/, reading left to right from index 0. Remaining groups follow the same recipe, and a final group shorter than three bytes is zero-padded to the next 6-bit boundary, with one = for two missing bytes or two = for one.
Frequently asked questions
Why is the Base64 form of this text longer than the text itself?
Base64 carries every 3 bytes of input as 4 characters. This text is 1 byte in UTF-8, so its encoded form runs 4 characters — a growth factor of about 4.00. Padding with the = sign tops the output up to a multiple of four.
Can this value be used directly in a URL?
Not unchanged when it contains + or /, because both are reserved in query strings. The URL-safe variant swaps them for - and _. For this text the two forms happen to be identical, since no + or / appears.
How do I get the original text back?
Paste the encoded string into the decoder on the homepage. It sniffs the input automatically, tolerates missing padding, and decodes through a UTF-8 bridge so multi-byte characters survive the round trip intact.
Other texts
Encoding something longer, or decoding in the other direction? The Base64Deco bridge handles multi-line input, files and image data URLs, or browse the full reference library.