Base64 Encoder Decoder
Encode UTF-8 text as standard Base64, or decode canonical Base64 as UTF-8 text.
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Text or encoded input | Text is processed in your browser. Maximum input: 1 MiB of UTF-8 text. |
| Calculation mode | encode/decode |
Understanding your result
The output applies the selected format or address convention. Encoding is not encryption; a valid address representation does not establish availability, reachability or security.
Common mistakes
- Using a different alphabet, padding, base, delimiter or address-prefix convention than the tool expects.
Check your calculation
- Where a reverse operation exists, round-trip a short known example. Compare structural results with the reference example rather than executing decoded text.
Calculation checks, sources and review limits
How do I encode text as Base64 or decode Base64 back to UTF-8 text?
Encode UTF-8 text as standard Base64, or decode canonical Base64 as UTF-8 text.
Common uses
- Encode UTF-8 text as standard Base64, or decode canonical Base64 as UTF-8 text.
How it works
Encode Unicode text into UTF-8 bytes and use the RFC 4648 alphabet with padding. Decode requires valid canonical padding and zero unused pad bits. Arbitrary binary that is not valid UTF-8 is rejected instead of displaying replacement characters. Base64 is an encoding, not encryption.
Worked example
Enter Text or encoded input: foobar; Calculation mode: encode. The result is Text: Zm9vYmFy.
FAQ
How do I encode text as Base64 or decode Base64 back to UTF-8 text?
Encode Unicode text into UTF-8 bytes and use the RFC 4648 alphabet with padding. Decode requires valid canonical padding and zero unused pad bits. Arbitrary binary that is not valid UTF-8 is rejected instead of displaying replacement characters. Base64 is an encoding, not encryption.
What assumptions and limits apply?
Treat encoded input as bytes; strict UTF8 decode may fail for arbitrary binary. Offer byte output instead of corrupting data.