Base64 Decoder
Decode standard Base64 into UTF-8 text with strict alphabet, padding, and byte validation.
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How to use Base64 Decoder
Read text stored as Base64 without uploading it. The decoder ignores whitespace, accepts valid optional padding, and reports malformed data instead of silently replacing invalid UTF-8.
- Paste a standard Base64 string.
- Run the decoder.
- Copy or download the UTF-8 text.
Good to know
- Up to 200,000 input characters. Binary data that is not UTF-8 is rejected.
- Base64URL uses a different alphabet; use the JWT Decoder for JWTs.
- Decoded content is displayed as inert text.
Common questions
Can it decode an image?
No. This decoder produces UTF-8 text, not binary files.
Are line breaks allowed?
Yes. Whitespace is removed before Base64 validation.
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