Is a UUID “URL safe”?

Question

Is a UUID URL safe? I want to use it as an alternate ID yet perhaps allowing access to the record as the ID in the URL. While I can use Ruby’s SecureRandom.urlsafe_base64(27) to obtain a random base64-encoded string of the same length, a UUID looks cleaner.

Answer 1

Yes.

• A UUID consists of only hexadecimal characters (a–f, 0–9) plus a hyphen (-).

• As per RFC 3986 (URI Syntax) §2.3, hyphen and hexadecimal characters are included in those explicitly unreserved:

  Characters that are allowed in a URI but do not have a reserved purpose are called unreserved. These include uppercase and lowercase letters, decimal digits, hyphen, period, underscore, and tilde.