How to Use the Base64 Encoder and Decoder
- Choose encode or decode mode: Select whether you want to convert text to Base64 or decode a Base64 string back to readable text.
- Enter your text or Base64 string: Paste your input into the text area. For encoding, type or paste plain text. For decoding, paste a valid Base64 string.
- Get instant results: The converted output appears immediately as you type. No buttons to click — the tool processes input in real time.
- Copy the result: Use the copy button to transfer the output to your clipboard with a single click.
Understanding Base64 Encoding
Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters: the uppercase letters A-Z, lowercase a-z, digits 0-9, and the symbols + and /. The encoding works by taking every three bytes of input (24 bits) and dividing them into four groups of 6 bits each. Each 6-bit group maps to one of the 64 characters, producing output that is approximately 33% larger than the original binary data.
Base64 is not encryption — it provides no security or confidentiality. Anyone can decode Base64 instantly. Its primary purpose is to ensure that binary data survives transport through systems designed to handle text. For example, email protocols were originally designed for ASCII text only; Base64 allows images, attachments, and other binary files to be embedded in email messages. Similarly, JSON and XML cannot contain raw binary data, so Base64 is used to embed images, fonts, and other binary resources directly in data files as data URIs.
The most common Base64 variant is RFC 4648, which uses the standard alphabet described above. A URL-safe variant replaces + with - and / with _ to avoid conflicts with URL path characters. When decoding, the tool automatically handles padding characters (=) and ignores whitespace. For developers working with APIs, data URIs, or configuration files, a reliable Base64 tool is an essential part of the daily toolkit.