SHA-1 Hash Generator

Generate SHA-1 hash from text instantly. Free online SHA-1 hash calculator. Note: SHA-1 is deprecated for security use. Client-side processing only.

Everything runs in your browser — your data is never sent to any server.

Why use a SHA-1 Hash Generator?

SHA-1 (Secure Hash Algorithm 1) produces a 160-bit hash value. While SHA-1 has been deprecated for security-sensitive applications due to demonstrated collision attacks, it remains relevant for legacy systems, Git commit hashes, and certain compliance requirements. Our tool uses the browser's Web Crypto API for efficient computation.

Key Features

  • Generate SHA-1 hash using the native Web Crypto API
  • Toggle between uppercase and lowercase output
  • Hash comparison for verification purposes

How to use

  1. Enter or paste your text in the input field
  2. The SHA-1 hash is generated instantly
  3. Copy the result or compare it with another hash

Technical Details

SHA-1 produces a 160-bit (20-byte) hash value, rendered as a 40-character hexadecimal string. It processes input in 512-bit blocks with 80 rounds. In 2017, Google demonstrated a practical collision attack (SHAttered), making SHA-1 unsuitable for digital signatures and certificates. However, it's still used in Git for commit identification.

FAQ

Should I use SHA-1 for security?

No, SHA-1 is no longer considered secure for cryptographic purposes. Collision attacks have been demonstrated. Use SHA-256 or SHA-3 instead for security applications.

Why does Git still use SHA-1?

Git uses SHA-1 primarily for object identification rather than security. The SHA-1 collision attack requires specific conditions that don't apply to Git's usage pattern. Git is also adding support for SHA-256.

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