Base64 Encode / Decode

Using the Base64 Encode / Decode

Choose the operation before entering text. Encoding converts the text to UTF-8 bytes and then Base64. Decoding expects those bytes to represent valid UTF-8 text; arbitrary binary files are not the same as text and may fail that check.

Worked example

Use the example inputs below to reproduce this result. These are the form's starting values, not recommended targets. Changing your inputs updates your result above; this worked example stays fixed for comparison. Results are rounded for display.

Method and assumptions

Uses standard Base64 with UTF-8 text. Base64 is an encoding, not encryption.

Know the format expected at the other end

Encoding works when the sender and receiver agree on the format and character representation. Check whether a value is already encoded before processing it, and decode only the intended layer. Encoding can make data suitable for transport, but it does not establish authenticity or confidentiality. A readable decoded value is not proof that its contents are trustworthy.

Common question

Why can valid Base64 still fail to decode here?

Base64 can represent any bytes, but this tool returns text. If the decoded bytes are not valid UTF-8, the text decoder rejects them. A binary-aware tool is needed to inspect that data without assuming it is text.