Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 back to text, with full Unicode support.
About the Base64 Encoder & Decoder
Choose encode or decode and paste the text. The tool converts it in your browser, treating text as UTF-8 so accents and emoji work, and shows the input and output sizes.
Base64 represents binary data with 64 printable characters, 4 characters for every 3 bytes (so output is about 33% larger). It's used for email attachments, data URLs and tokens. It's an encoding, not encryption: anyone can decode it. Text is converted as UTF-8, so emoji and accents work.
The formula
Every 3 bytes (24 bits) → 4 characters of 6 bits
Worked example
Encoding “Hello, world! 👋”
- 18 bytes of UTF-8
- 24 Base64 characters: SGVsbG8sIHdvcmxkISDwn5GL
Questions people ask
What is Base64URL?
A variant using - and _ instead of + and /; this decoder accepts both.
Is Base64 secure?
No, it's trivially reversible.