All Base64 guides
Newest first. Each one names the runtime its outputs came from.
Base64 in a Query String: Four Dropped Plus Signs Decode With No Error
An unescaped + arrives as a space and atob deletes it. At 128 bytes, 15.0% of payloads decode into the wrong bytes with no error.
Base64 in Go: Four Encodings and the Strictest Decoder
Four encodings, no conversion step, and the strictest decoder of the three languages measured.
Base64 Image Data URIs: The Size You Actually Pay
Measured overhead, the caching cost people forget, and why SVG usually wins for icons.
Base64 vs Hex: Which Encoding, and When It Matters
Hex is exactly 2 characters per byte, Base64 about 1.33. Measured comparison and how to choose.
Base64 in Python: b64encode, urlsafe and the bytes/str Split
b64encode takes bytes not str, urlsafe vs standard, and why Python rejects padding that JavaScript accepts.
Base64 in JavaScript: The Ways btoa and atob Break
Why btoa() throws on non-Latin-1 text, the correct encode paths in browser and Node, and the exact conditions under which atob() fails.