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Fix Base64 invalid character errors

Base64 decoding fails when the string includes unsupported characters, whitespace in the wrong place, URL-safe variants, or missing padding.

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HappyFormatter tools process pasted snippets client-side for quick, privacy-first developer workflows.

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HappyFormatter tools process pasted snippets client-side for quick, privacy-first developer workflows.

Fix steps

  1. 1 Remove characters outside the Base64 alphabet.
  2. 2 Convert URL-safe - and _ to + and / if needed.
  3. 3 Add padding so length is divisible by four.

Invalid Base64

The asterisk is not part of the Base64 alphabet.

SGVsbG8*

Output

Invalid character

Fixed Base64

Use valid characters and correct padding.

SGVsbG8=

Output

Hello

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