Base64url alphabet
03The URL-safe alphabet changes two symbols without changing the six-bit grouping.
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
DIAGRAM§ 5 ↗
RFC 4648 · § 5EXAMPLE
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03
Apply the profile
Padding behavior comes from the consuming protocol, not the alphabet name alone.
Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
Read the updated RFC section ↗
Base64url uses - and _ instead of + and /.
- Base64url uses - and _ instead of + and /.
- It is distinct from standard Base64.
- Omitting padding requires an explicit profile or an implicitly known data length as described in §5.
Examples are illustrative. Consult the linked RFC and its errata for implementation details.
Read the RFC section ↗Diagrams simplify the RFC. Read the linked sections for complete requirements.
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