RFC 9923 - The FNV Non-Cryptographic Hash Algorithm

• Status: Informational
• Published: February 2026
• Stream: Independent
• Pages: 111
• Errata: RFC Editor Errata

Abstract

FNV (Fowler/Noll/Vo) is a fast, non-cryptographic hash algorithm with good dispersion. This document makes FNV information and open-source code for the specified FNV sizes available to the Internet community.

Contents

• 1. Introduction
• 2. FNV Basics
• 3. Other Hash Sizes and XOR Folding
• 4. Hashing Multiple Values Together
• 5. FNV Constants
• 6. Security Considerations
• 7. Historical Notes
• 8. The Source Code
• 9. IANA Considerations
• 10. References
• Appendix A. Work Comparison with SHA-1 and SHA-256
• Appendix B. Previous IETF FNV Code
• Acknowledgements
• Authors' Addresses

Related Resources

• Official Text: RFC 9923
• Official Page: RFC 9923 DataTracker
• Errata: RFC Editor Errata