Common Base64 Use Cases and Pitfalls
A practical tour of Base64 in development: inlining in APIs, email attachments, URL transport, certificate storage — plus size and security reminders.
Inlining binary inside text protocols (JSON / XML / YAML): for example putting an avatar or attachment into a field as Base64, avoiding a separate upload and reference.
Email and legacy systems: many mail protocols transport attachments as Base64, and some restricted or older channels accept text only, so content must be encoded first.
URLs and storage: carrying binary fragments in text-only fields such as certain URL parameters, cookies, or config entries; certificates and keys are likewise usually stored as Base64 text.
Two reminders: Base64 grows data by roughly one third, so avoid it for large files; and it is encoding, not encryption — sensitive data must be properly encrypted before transport or storage.