Base64 Encoder

A payload has to travel as ASCII. Base64 Encoder turns the text you paste into standard Base64.

Standard alphabet, including UTF-8

Paste the text and run Process. The encoder uses the standard alphabet: A to Z, a to z, digits, plus, and slash, with equals padding when the length needs it. Letters outside ASCII are encoded as UTF-8 first, so a non-English sentence round-trips with Base64 Decoder. This is not the URL-safe alphabet. Minus and underscore are not substituted, and padding is not stripped. There is no file upload. A data URI is something you assemble after you copy the string. This box does not add a data: prefix for you.

Encoding is not a secret

Anyone who can see the string can decode it. Do not put a password or a private key here and call the result safe. Hash Generator digests text. File Hash digests a file. URL Encoder percent-encodes a query value, which is a different escaping. JWT Decoder reads a three-part token. None of those hide a string the way a cipher would. If you need the URL-safe form, this screen will not swap the characters for you. Count the padding equals signs if the other system is strict about them.

When the decoder will not match

A decoder that expects base64url will reject plus, slash, or the padding. Strip or swap those only if the other system asked for that alphabet. A line break you paste in the middle becomes part of the encoded text. Trim the input to the exact characters you meant. The work stays in this browser. A copied string with a trailing space will not match later. Decode it once with Base64 Decoder before you embed it, so you know the round trip works.