Generate SHA1 hashes online for legacy compatibility checks.
About
SHA-1 is a 160-bit hash algorithm from the SHA family with known collision attacks. It is still present in legacy environments but is deprecated for modern cryptographic security.
Specifications
Output Size160 bits
StandardFIPS 180-1
Standard Year1995
Use Cases
—Legacy interoperability
—Historical checksum comparison
Security Notice
Avoid SHA-1 for new security-sensitive designs.
Frequently Asked Questions
SHA-1 has known collision weaknesses and is deprecated for most cryptographic uses. Prefer SHA-256 or stronger alternatives.
SHA-1 was deprecated after successful collision attacks demonstrated in 2017 (SHAttered) and 2020 (SHAmbles). These attacks allow creating two different documents with identical SHA-1 hashes, making it unsuitable for digital signatures and certificates. Major browsers no longer accept SHA-1 certificates.
Replace SHA-1 with SHA-256 or SHA-384 in most applications. For file integrity, recalculate checksums using SHA-256. For digital signatures, upgrade your certificate infrastructure. For version control systems like Git, note that while Git uses SHA-1, it includes collision detection mechanisms.