Encoding
Hello, World! → SGVsbG8sIFdvcmxkIQ==
Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 to text, with full Unicode support and URL-safe output.
Runs in your browser — nothing you enter is sent to a server.
How the Base64 Encoder & Decoder works
Choose Encode to turn text into Base64 or Decode to turn Base64 back into text. The result updates as you type. Text is converted to UTF-8 first, so emoji and every language work — unlike the browser's basic btoa(), which fails on them.
When decoding, spaces, line breaks, missing = padding and the URL-safe alphabet are all accepted. If the Base64 is invalid, or decodes to a file rather than text, the tool tells you instead of showing garbage.
Formula
3 bytes (24 bits) → 4 characters (6 bits each)
Each group of 6 bits becomes one of 64 characters: A–Z, a–z, 0–9, + and /. Output is padded with = to a multiple of 4, so Base64 is about 33% larger than the original.
Examples
URL-safe Base64
+ becomes -, / becomes _, and padding is dropped, so the result can go in URLs and file names: Pz8+ → Pz8-.
Frequently asked questions
Is Base64 encryption?
No. Base64 is an encoding, not encryption — anyone can decode it. Never use it to protect passwords or secrets.
Where is Base64 used?
In email attachments, data URLs (data:image/png;base64,…), HTTP Basic authentication headers, JSON Web Tokens and anywhere binary data has to travel as plain text.
Is my data uploaded?
No. Encoding and decoding happen entirely in your browser.
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