Encode plain text into Base64, free and instant.
Base64 encoding turns arbitrary text or binary data into a set of 64 printable ASCII characters, which is why it shows up in data URIs, email attachments, and API tokens — formats that need to move binary-safe data through text-only channels.
This tool encodes UTF-8 text into Base64 or decodes Base64 back into readable text, entirely client-side. Encoding is safe for any input; decoding will fail with an error if the pasted string is not valid Base64, which usually means it was truncated or mixed with other text.
Note that Base64 is an encoding, not encryption — anyone can decode it, so it should never be used to protect sensitive data.
Worked example: the text "Man" encodes to "TWFu". Base64 works by taking 3 bytes (24 bits) of input at a time and regrouping those same 24 bits into four 6-bit chunks, since 6 bits is exactly enough to represent 64 possible values (0-63), each mapped to one of the 64 printable characters (A-Z, a-z, 0-9, +, /). "M" (01001101), "a" (01100001), and "n" (01101110) concatenate to 24 bits, which split into four 6-bit groups — 010011, 010110, 000101, 101110 — mapping to characters 19, 22, 5, and 46 in the Base64 alphabet: "T", "W", "F", "u". This is also why Base64 output is always about 33% longer than the input: 3 bytes of data become 4 characters of output.
No. It is a reversible encoding scheme, not a security measure. Anyone with the encoded string can decode it instantly.
The input is not valid Base64 — often because it was copied with line breaks removed, or it is actually a JWT (which has three dot-separated Base64url segments, not one plain Base64 string).
This version handles text input only. For file-to-Base64 conversion, use a dedicated file-upload tool.