Base64 Encoder & Decoder

Encode text to Base64 or decode Base64 strings back to plain text. Supports standard and URL-safe Base64. Fully client-side.

URL-safe Base64 (replace + with - and / with _)

Base64 Output

What is Base64 encoding?

Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). It is commonly used to encode binary data for transmission over text-based protocols like email (MIME) and embedding images in CSS/HTML as data URIs.

Base64 increases the size of the encoded data by approximately 33% but ensures safe transmission through systems that may not handle binary data correctly.

URL-safe Base64

Standard Base64 uses + and / characters which have special meanings in URLs. URL-safe Base64 (Base64URL) replaces these with - and _ for safe use in URLs and filenames. It is used in JWT tokens, OAuth, and other web security contexts.