Base64 Decode

Decoding Base64 back into readable text

Base64 strings turn up in many places: email headers and attachments, configuration files, API responses, authentication headers, data URIs and parts of tokens. Decoding them is often the quickest way to see what a system is actually sending. This tool turns Base64 back into readable text and copes with the small inconsistencies that real-world strings often contain.

Line breaks and spaces are ignored, which helps when the string has been copied from an email or wrapped across several lines. Missing padding at the end is added automatically. Both the standard and URL-safe alphabets are accepted, so strings that use minus and underscore instead of plus and slash decode correctly. Text is read as UTF-8, so Indian languages and emoji come out as intended.

If the output looks like random symbols, the original data was probably not text. It may be an image, a compressed file, an encrypted value or another binary format. In that case, the decoded bytes cannot be shown meaningfully as characters, and you would need a tool designed for that file type. For Base64 images in a data URI, paste the full string into your browser's address bar to view the picture. Be careful when decoding values from unknown sources, especially if the result contains links or code, and never run decoded scripts you do not fully understand. Decoding happens entirely in your browser, so tokens and private messages are not shared. It is also a useful way to check what a system is really storing. A data URI prefix at the start is removed automatically before decoding.