Base64 Encoder / Decoder
Encode any text to Base64 format or decode Base64 strings back to plain text.
Base64 encoding converts binary data into a string of 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). It is used wherever binary data needs to be transmitted or stored as text: email attachments (MIME), data URIs for embedding images in HTML or CSS, JSON Web Token signatures, HTTP Basic Authentication headers, and API keys. The encoded output is approximately 33% larger than the original input because 3 bytes of binary data become 4 characters of Base64.
Frequently asked questions
Is Base64 encryption?
No. Base64 is encoding, not encryption. It is easily reversible without any key. Anyone can decode Base64 instantly. Do not use it to protect sensitive data. It is for format conversion and compatibility, not security.
What is Base64url?
Base64url is a variant that replaces + with - and / with _ and omits padding characters, making it safe for use in URLs and filenames. JWTs use Base64url encoding for their header and payload sections.