Base64 Encode / Decode
Encode text to Base64, or decode a Base64 string back to text, instantly in your browser.
How to use the Base64 Encode/Decode
- Choose Encode to convert text to Base64, or Decode to convert Base64 back to text.
- Paste your text or Base64 string.
- Click Run and copy the result.
How the Base64 Encode/Decode works
Base64 represents binary data using 64 safe ASCII characters: A-Z, a-z, 0-9, + and /. The encoder first converts your text to UTF-8 bytes, then takes them three bytes (24 bits) at a time and splits each group into four 6-bit values, each mapped to one Base64 character. If the input isn't a multiple of three bytes, = padding is added at the end.
That's why Base64 output is about 33% larger than the input. Base64 is an encoding, not encryption: anyone can decode it. It's used for email attachments, data URIs, HTTP Basic authentication headers and JWTs (which use the URL-safe Base64URL variant).
Frequently asked questions
- Is this tool free?
- Yes. Encode and decode Base64 at no cost, with no account required.
- Does it support Unicode text?
- Yes. Text is encoded as UTF-8 before Base64 encoding, so non-English characters and emoji work correctly.
- Is Base64 encryption?
- No. Base64 is a reversible encoding that anyone can decode. Use the AES Encrypt/Decrypt tool if you need to protect the content.
- Does my text leave my browser?
- No. The conversion runs entirely in your browser, so your text is never sent to a server.