Base64 Encoder and Decoder
Encode text to Base64 or decode Base64 back to text, entirely in your browser with full Unicode support.
About this tool
Base64 represents arbitrary binary data using 64 safe printable characters, which is why it appears anywhere binary content must travel through text: email attachments, data URLs, JSON payloads, basic authentication headers, and cryptographic keys. It is an encoding, not encryption; anyone can reverse it.
This tool handles full Unicode correctly by encoding text as UTF-8 bytes before the Base64 step, so multilingual text, accented characters, and symbols round trip exactly. Everything runs locally in your browser, making it safe to use with content you would not paste into an online service.
Frequently asked questions
Is Base64 secure?
No. It is a reversible encoding with no key. Anything Base64 encoded should be treated as plain text for security purposes.
Why is Base64 output longer than the input?
Every 3 bytes of input become 4 characters of output, so encoded data is about 33 percent larger, plus up to two = padding characters.