Character Encoding Troubleshooting Handbook: Mojibake, URL Encoding, and Base64 Explained

Chinese turning into ??? or é”±? %E4%B8%AD unreadable? This handbook classifies by symptom — real mojibake, URL percent-encoding, Unicode escaping, and Base64 with Chinese, plus an encoding primer and a debugging workflow.

Base64 Decode Shows Garbled Text or Black Question Marks for Chinese — How to Fix

Base64 decode turns Chinese into mojibake or black question marks? Explains the root cause — Base64 encodes bytes, not characters — and gives command-line, code, and online-tool fixes, all processed locally.