Text becomes bytes before Base64
Text encoding first converts characters to UTF-8 bytes, then converts those bytes to Base64. For example, Hello becomes SGVsbG8=. Decoding reverses the process, showing text only when the bytes form valid UTF-8.
A file uses its original bytes directly. This can encode binary data without pretending it is text. Your selected file and text are processed in this browser and are not uploaded by the tool.
Check the alphabet and padding
Standard Base64 uses letters, digits, +, /, and trailing = padding when needed, unless the receiving protocol permits its omission. The decoder accepts whitespace, unpadded values, URL-safe characters, and a Base64 data-URL prefix. It rejects misplaced padding and nonzero unused bits instead of silently accepting a malformed value. RFC 4648 defines these encodings.
Encoding does not hide a password, token, or other secret from someone who can read the output. Treat encoded sensitive data with the same care as its source.
No record of your text is kept.