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MD5 vs SHA-1

MD5 vs SHA-1 compared — length, speed and security. Both are broken for security; here is what each is still useful for.

MD5 (128-bit) and SHA-1 (160-bit) are both older hash functions that are broken for security — practical collisions exist for both. Neither should be used for signatures or passwords; use SHA-256 instead.

MD5 vs SHA-1 at a glance

MD5 SHA-1
Output 128-bit (32 hex) 160-bit (40 hex)
Speed Faster Fast
Collisions Broken Broken
Safe for security? No No

When to use MD5

Use MD5 only for non-security checksums (deduplication, corruption checks).

When to use SHA-1

Use SHA-1 only where a legacy system requires it; prefer SHA-256 for anything new.

Tools for MD5 & SHA-1

MD5 vs SHA-1

Is SHA-1 more secure than MD5?

Marginally, but both are broken — collision attacks are practical for each. For any security use (signatures, certificates, passwords) move to SHA-256.