Base64 encoder and decoder
Encode Unicode text as standard Base64 or decode standard Base64 back to text.
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Interactive tool
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The Base64 tool converts text to UTF-8 bytes before standard Base64 encoding and reverses that process during decoding. Base64 is designed to represent bytes with printable characters; it is not a security mechanism.
When to use this tool
- Encode a short Unicode text value for a text-only field.
- Decode a standard Base64 string to inspect its UTF-8 text.
How to use
- Enter text for Encode or a Base64 string for Decode.
- Choose the direction; switching modes can reuse the valid output.
- Review and copy the local result.
Example
Unicode text
Encoding Hello 世界 first converts the characters to UTF-8 bytes, then produces a standard padded Base64 string.
How it works
- UTF-8 conversion is performed with TextEncoder and TextDecoder; the Base64 alphabet and padding follow the standard browser btoa/atob representation.
Limits and notes
- Base64 is an encoding, not encryption; anyone with a decoder can recover the content.
- The tool implements strictly padded standard Base64, not the Base64url alphabet used in some URLs and tokens.
- Decoded bytes must form valid UTF-8 text; arbitrary binary data is rejected.
Frequently asked questions
Why is the Base64 output longer?
Base64 represents each 3 input bytes with 4 printable characters, plus possible padding.
Can Base64 protect a password?
No. It provides no confidentiality and must not be treated as encryption.
Does it support Chinese text?
Yes. Text is converted to UTF-8 bytes before encoding and decoded back with UTF-8.
References
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