Base64 Encode / Decode

Base64 encodes binary or text data as ASCII characters so it can be safely embedded in URLs, data URIs, JSON, emails and other text-only contexts.

Yes. Click Open file in Encode mode and the file is encoded in your browser. Tick Output as data URI to get a data: URL you can embed in HTML or CSS. In Decode mode, decoded images are previewed and any binary result can be downloaded as a file.

Base64 encodes bytes, not letters, so text has to be turned into bytes first. UTF-8 is the usual choice; pick another destination charset (such as ISO-8859-1 or Windows-1251) if the receiving system expects it. When decoding, Auto-detect checks for a byte-order mark, then valid UTF-8, then falls back to Windows-1252; choose the source charset yourself if the text looks garbled.

Each line separately encodes or decodes every line as its own value, which is handy for lists. Split into 76-character lines wraps output the way MIME email does. Newline separator decides whether line breaks in your text are encoded as LF or CRLF.

Base64URL (RFC 4648 §5) swaps + and / for - and _ and drops the = padding, so the value can sit in a URL or a JWT without escaping. Decode mode accepts both alphabets automatically.

No. Base64 is an encoding, not encryption. It is easily reversible and provides no security — never use it to protect sensitive data.

Yes. Choose Decode and paste the Base64, with or without a data: prefix. An image result is previewed, and any binary result, such as a PDF, can be downloaded as a file.