Use Base64 alphabets, padding and byte formats

How to use the workspace

1. Choose encode or decode and select standard or URL-safe alphabet.
2. Choose UTF-8 for text or hex for explicit byte values. That selection describes the raw side of the conversion.
3. Choose padding behavior for encoding, then run and inspect the byte count.

A concrete starting point

UTF-8 input: hello
Standard Base64: aGVsbG8=
Hex for the same bytes: 68656c6c6f

The example illustrates the difference between bytes and the textual representation of those bytes.

Read the result carefully

Standard Base64 uses + and /; the URL-safe alphabet uses - and _. Padding affects the encoded representation, not the underlying payload. Decoding supports valid padded or unpadded input and reports malformed data rather than inventing a result.

Common mistakes to avoid

• Encoding does not mean encrypting; anyone with the value can decode it.
• Arbitrary binary bytes may not form valid UTF-8. Choose hex output when inspecting binary content.
• Do not assume all decoders accept mixed alphabets or malformed padding.

Limits & privacy

1 MiB input under a 2 MiB output envelope. UTF-8 and hex are explicit; there is no automatic detection or input history.