SHA1 Hash Generator

What the SHA1 Hash Generator does

This tool generates a SHA-1 hash of any text you enter, computed locally using your browser's built-in crypto engine — useful for compatibility with older systems and Git, which still uses SHA-1 internally for commit identifiers.

How to use it

1. Type or paste the text you want to hash.
2. Click Generate SHA-1.
3. Click Copy hash to copy the resulting hex string.

Common uses

• Reproducing or verifying a SHA-1 hash used by a legacy system or protocol.
• Understanding how Git computes object hashes for commits and blobs.
• Checking file integrity against an older checksum published in SHA-1 format.
• Testing SHA-1 output for coursework covering cryptographic hash functions.
• Comparing SHA-1 output against SHA-256 output for the same input to see the difference.

Good to know

SHA-1 is no longer considered cryptographically secure for anything security-sensitive — practical collision attacks have been demonstrated since 2017 — so for new projects needing hash security, SHA-256 or stronger is the appropriate choice. SHA-1 remains common in legacy systems and in Git's internal object model, which is why it's still worth having on hand even though it shouldn't be used for new security-critical applications.

SHA-1 was the dominant cryptographic hash standard for well over a decade before researchers at Google and CWI Amsterdam demonstrated a practical collision attack in 2017, which is the point at which major browsers and certificate authorities began actively deprecating it for security purposes. Git's continued internal use of SHA-1 for object identifiers is a separate case — it's used there primarily for content addressing and integrity rather than as a security boundary against a malicious actor, which is a meaningfully different threat model.