Base64 Encode / Decode

 

About Base64 Encoder

Base64 encodes binary data as text using 64 ASCII characters (A–Z, a–z, 0–9, + and /, with = padding). It is used for data URIs, email attachments (MIME), HTTP Basic authentication, and embedding binary data in JSON or XML.

This tool encodes and decodes Base64 with full Unicode support: text is converted to UTF-8 bytes first, so Korean, Japanese, emoji and other non-Latin characters round-trip correctly. You can also encode or decode each line separately.

How to use

  1. Enter plain text to encode, or a Base64 string to decode.
  2. Click Encode or Decode.
  3. Enable Line-by-line to process every line independently, and Auto update to re-run as you type.

FAQ

Is Base64 encryption?

No. Base64 is an encoding, not encryption — anyone can decode it. Never use it to protect passwords or secrets.

Why does Base64 output end with = or ==?

Base64 encodes 3 bytes into 4 characters. When the input length is not a multiple of 3, = padding characters are added so the output length is a multiple of 4.

How much bigger is Base64 than the original?

About 33% larger: every 3 bytes become 4 characters.

What is Base64URL?

A URL-safe variant that replaces + with - and / with _, and usually omits padding. It is used in JWTs and URLs.