Hash Functions Explained: MD5, SHA-1, SHA-256
Practical differences, security tradeoffs, and migration guidance for common hash algorithms.
Last updated: May 4, 2026
What hashes are for
Hashes produce deterministic fingerprints for integrity checks and deduplication. They are one-way functions, not reversible encoding.
MD5 and SHA-1 caution
MD5 and SHA-1 are collision-prone and should not be used for security-sensitive signatures. Keep them only for legacy compatibility.
Default recommendation
For modern systems, use SHA-256 as the baseline unless protocol requirements dictate something else.