SHA-1 Hash Generator Online

SHA-1 is an older hashing algorithm that produces a 40-character (160-bit) hex digest. It's still in common use for non-security purposes — Git uses it to identify commits, and many checksums you'll find on download pages are SHA-1. This tool generates SHA-1 hashes from any text input.

How it works

The hash is computed client-side using the browser's SubtleCrypto API. Your input stays in your browser — nothing is sent to a server.

How to use it

1. Paste or type your input text
2. Click Generate Hash
3. Copy the 40-character hex output

A few things worth knowing

• SHA-1 is cryptographically broken for security use: Practical collision attacks have been demonstrated (SHAttered, 2017). You can construct two different inputs that produce the same SHA-1 hash. For anything where integrity genuinely matters (code signing, TLS, password hashing), use SHA-256 instead
• Still fine for non-security checksums: Git commit IDs, legacy file verification where collision attacks aren't a threat model, and systems that just need a compact fingerprint of data
• 40 characters: SHA-1 always outputs 40 hex characters regardless of input length

FAQ

Does Git still use SHA-1? Yes, though Git is gradually transitioning to SHA-256. The SHA-1 usage in Git is for content addressing (deduplication), where the collision risks in practice are lower than in cryptographic signing.

Should I use SHA-1 for new projects? For checksums or data deduplication, it's acceptable. For any security-sensitive use — password hashing, digital signatures, certificate validation — use SHA-256 or SHA-512.

Is it safe to generate hashes here? Yes. Everything runs locally in your browser via the Web Crypto API.

Related Tools

• SHA-256 Hash Generator
• MD5 Hash Generator