Base64 Encoder
Encode text as Base64 for data URLs, HTTP Basic auth headers, or systems that only accept ASCII.
Your input stays in your browser. Nothing is uploaded.
Input
Output
About this tool
The text is first converted to UTF-8 bytes, then every 3 bytes become 4 characters from the standard Base64 alphabet (A–Z, a–z, 0–9, + and /), with = padding at the end. Base64 is an encoding, not encryption: anyone can decode it, so it does not protect secrets.
Limits
- Base64 is an encoding, not encryption. Anyone can reverse it. Do not use it to hide passwords, tokens, or personal data.
- The alphabet is the standard one (+, /, and = padding), not the URL-safe alphabet used inside JWTs.
- Binary files encoded as text will not round-trip through this page as readable text. Use Image to Base64 for images.
How to use it
- Type or paste the text to encode.
- Copy the Base64 output.
- To check it, paste the output into the Base64 Decoder.
Output length = 4 × ⌈bytes ÷ 3⌉
Examples
ASCII
"hello" (5 bytes) encodes to "aGVsbG8=" (8 characters).
Accented text
"é" is 2 bytes in UTF-8, so it encodes to "w6k=".
Basic auth
"user:pass" encodes to "dXNlcjpwYXNz", used in the header Authorization: Basic dXNlcjpwYXNz.
FAQ
Is Base64 secure?
No. It only changes the representation. Anyone with the string can decode it instantly.
Why is the output longer than the input?
Base64 uses 4 characters for every 3 bytes, so output is about 33% larger, plus padding.
Does it produce URL-safe Base64?
No. It uses + and /. For URL-safe Base64 (as in JWTs), replace + with -, / with _, and remove the = padding.
Is my text uploaded?
No. Encoding runs in your browser.