Base64 Encoder/Decoder
Safely convert text to bytes and Base64, or decode Base64 back to text.
Auto detection identifies UTF formats conservatively.
Auto · Using UTF-8
About character encoding
Base64 is not encryption. Auto Encode uses UTF-8, and ambiguous legacy Decode requires a manual encoding choice.
Processed only in your browser
Your input and result are never sent to a server or stored.
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What does the Base64 Encoder/Decoder do?
It converts text to Base64 through an explicit character encoding, or decodes Base64 bytes back into text. This is useful when inspecting encoded API fields, email data, or legacy text payloads.
How to use it
- 1
Choose a direction
Use Encode for plain text or Decode for an existing Base64 value.
- 2
Set the character encoding
Auto uses UTF-8 for encoding. Select a known legacy encoding when the source requires it.
- 3
Convert and review
Run the conversion, check the applied encoding, and copy the result when it looks correct.
Practical examples
UTF-8 text
Hello 안녕하세요 😀
→ Encode → Decode → original textLegacy text
Select EUC-KR or Shift_JIS
Decode bytes using that character setProcessing rules and limitations
Byte-based conversion
Text is converted to bytes before Base64 is produced; Unicode text is not passed directly to btoa.
Loss prevention
Encoding fails instead of silently replacing characters that the selected character set cannot represent.
Auto detection
Base64 does not store its original character encoding, so a detected decode encoding is an estimate unless a BOM identifies it.
Conversion stays in your browser
Text, bytes, and Base64 results are processed locally and are not sent to or stored on this site's server.
Frequently asked questions
Is Base64 encryption?
No. Anyone can decode it, so it must not be used to protect secrets.
Why does decoded text look corrupted?
The bytes were probably decoded with a different character encoding. Select the encoding used by the source.
Can I decode Base64 without padding?
Valid unpadded input is normalized where possible, while malformed Base64 is rejected.