Fix

Fix Base64 Invalid Padding Error

Base64 strings must have a length that is a multiple of 4, padded with = characters. Invalid characters or wrong encoding variant cause decode failures.

Open Base64 Encoder / Decoder

Padding Rules

Standard Base64 pads with = or == at the end. Some decoders accept unpadded input; others require exact padding.

Invalid Characters

Only A-Z, a-z, 0-9, +, /, and = are valid in standard Base64. Whitespace and newlines in PEM files should be stripped before decoding.

URL-Safe Variant

If the string contains - and _ instead of + and /, enable URL-safe mode in the Base64 tool.