Base64DecoBase64 Encoding Reference Library
Every page in this library takes a single text and shows its complete Base64 picture: the standard encoding, the URL-safe variant, the underlying UTF-8 bytes and the grouping arithmetic that produces the output. It is the fastest way to confirm an encoding by eye or to pick up how the alphabet maps to bits. Choose an entry below.
Frequently asked questions
What does each reference page show?
One text and its encodings: the standard Base64 string, the URL-safe variant when it differs, the UTF-8 bytes in hex, and a step-by-step derivation of the first bytes through the 6-bit grouping that defines the format.
Why do some entries encode to different lengths?
Output length follows byte count, not character count. Multi-byte UTF-8 characters such as accented letters or emoji add bytes, so the encoded string grows even when the text looks the same length on screen.
For anything longer than a word or phrase, the Base64Deco bridge encodes and decodes arbitrary text, files and data URLs with automatic direction sniffing.