SHA-1 Hash Generator & Verifier Tool

Generate SHA-1 hashes for text input or verify existing hashes. SHA-1 produces a 160-bit hash value, commonly used in Git commits and legacy systems. Note: SHA-1 is cryptographically deprecated and should not be used for new security applications.

Operation Mode

SHA-1 Algorithm Info

Output Length: 160 bits (40 hex chars)

Security Level: Deprecated (Not Secure)

Use Case: Git Commits, Legacy Systems

Input Text

Enter text to generate SHA-1 hash

0 characters

SHA-1 Hash

Generated SHA-1 hash (160-bit)

Hash Statistics

Input Characters

Input Bytes

Hash Characters

Hash Bits

Quick Examples

Security Notice

SHA-1 is cryptographically deprecated due to collision vulnerabilities. It should not be used for new security applications.

Known Issues:

• Collision attacks demonstrated
• Not suitable for digital signatures
• Deprecated by major browsers
• Faster than MD5 but still insecure

Recommended Alternatives:

• SHA-256 for general security
• SHA-512 for high security
• bcrypt for password hashing
• SHA-3 for new applications

What is SHA-1?

SHA-1 (Secure Hash Algorithm 1) is a cryptographic hash function that produces a 160-bit hash value, typically represented as a 40-character hexadecimal string. While more secure than MD5, SHA-1 is now considered cryptographically broken and has been deprecated for security applications since 2017.

Key characteristics of SHA-1:

160-bit output: Always produces 40 hex characters
Deterministic: Same input = same hash
Git standard: Used for commit identifiers
One-way function: Cannot reverse to original
Collision vulnerable: Theoretical attacks exist

Example: "Hello" → "aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d"

SHA-1 hash generation example showing text to hash conversion — SHA-1 hash generation visualization

⚠️ Deprecation Warning

SHA-1 is cryptographically deprecated and should not be used for new security applications:

Collision attacks: Practical attacks demonstrated in 2017
Browser deprecation: Major browsers no longer trust SHA-1 certificates
Industry migration: Standards bodies recommend SHA-256 or higher
Legacy support only: Use only for backward compatibility

Migrate to SHA-256 or SHA-512 for all new applications.

Features of Our SHA-1 Tool:

Instant generation - Real-time SHA-1 hash calculation
Hash verification - Compare generated vs expected hashes
Deprecation warnings - Clear information about SHA-1 status
Git compatibility - Verify Git commit hashes
Detailed statistics - Input/output length and bit information
Copy functionality - Easy hash copying for external use
Educational examples - Common text hash demonstrations
Migration guidance - Recommendations for secure alternatives

How to Use the SHA-1 Hash Tool

1. Choose Operation Mode

Select "Generate Hash" to create SHA-1 hashes from text, or "Verify Hash" to compare a generated hash against an expected value.

2. Enter Your Input

Type or paste your text in the input field. The SHA-1 hash will be generated automatically as you type.

3. Copy or Verify Results

Copy the generated hash for use elsewhere, or paste an expected hash in verification mode to check if they match.

4. Consider Migration

Review the security warnings and consider migrating to SHA-256 or SHA-512 for new applications requiring cryptographic security.

SHA-1 Hash Examples

Input	SHA-1 Hash	Use Case
Empty String	da39a3ee5e6b4b0d3255bfef95601890afd80709	Default/empty file check
Hello World	0a4d55a8d778e5022fab701977c5d840bbc486d0	Testing and examples
password123	482c811da5d5b4bc6d497ffa98491e38b93f02f7	⚠️ Deprecated for passwords
The quick brown fox...	2fd4e1c67a2d28fced849ee1bb76e7391b93eb12	Standard test string

SHA-1 in Git Version Control

Git Commit Hashes

Git uses SHA-1 to generate unique identifiers for commits, trees, and objects:

# Git commit with SHA-1 hash

commit a1b2c3d4e5f6789abcdef1234567890abcdef123

Author: John Doe <[email protected]>

Date: Mon May 27 10:00:00 2025 +0000

Add new feature implementation

Note: Git is transitioning to SHA-256 for new repositories. The Git project has been working on SHA-256 migration since the collision attacks on SHA-1 were demonstrated.

SHA-1 Security Timeline

1995 - Introduction

SHA-1 published by NIST as a federal standard, replacing SHA-0.

2005 - First Concerns

Cryptographers identify theoretical weaknesses in SHA-1's collision resistance.

2011 - NIST Deprecation

NIST formally deprecates SHA-1 for digital signatures and recommends SHA-2.

2017 - SHAttered Attack

Google demonstrates practical SHA-1 collision attack, proving it's broken.

2020 - Browser Sunset

Major browsers completely phase out SHA-1 certificate support.

Current Legitimate Uses for SHA-1

Despite security limitations, SHA-1 still has valid non-security applications:

Git Version Control - Commit and object identification (transitioning to SHA-256)
Legacy System Support - Maintaining compatibility with older systems
File Checksums - Detecting corruption in non-security contexts
Cache Keys - Generating unique identifiers for caching
Torrent Files - BitTorrent protocol piece verification
Archive Verification - Verifying integrity of archived files
Educational Purposes - Learning about hash functions and cryptography

Secure Alternatives to SHA-1

SHA-2 Family

SHA-224: 224-bit

SHA-256: Recommended

SHA-384: 384-bit

SHA-512: High Security

Use for digital signatures, certificates, and general cryptographic purposes

Modern Alternatives

SHA-3: Latest Standard

BLAKE2: High Performance

BLAKE3: Fastest

bcrypt: For Passwords

Use for new applications requiring strong cryptographic security

Migration Guide

Steps to Migrate from SHA-1

Audit Current Usage

Identify all systems and applications currently using SHA-1 for security purposes.

Choose Replacement

Select SHA-256 for general use, SHA-512 for high security, or bcrypt for password hashing.

Update Code

Replace SHA-1 function calls with the chosen alternative throughout your codebase.

Test Thoroughly

Verify that the migration doesn't break existing functionality or data integrity.

Gradual Rollout

Deploy the changes gradually, monitoring for any issues or compatibility problems.

Explore these more secure hashing alternatives:

SHA-256 Hash Generator

Generate cryptographically secure SHA-256 hashes - the recommended replacement for SHA-1.

Try our SHA-256 tool →

SHA-512 Hash Generator

Generate high-security SHA-512 hashes with 512-bit output for maximum security.

Try our SHA-512 tool →

bcrypt Password Hasher

Securely hash passwords using bcrypt - much better than SHA-1 for password storage.

Try our bcrypt tool →

MD5 Hash Generator

Generate MD5 hashes for legacy compatibility (also deprecated for security).

Try our MD5 tool →

Frequently Asked Questions

Is SHA-1 still safe to use?

SHA-1 is not safe for security applications due to demonstrated collision attacks. However, it's still acceptable for non-security uses like Git commits and file checksums where collision resistance isn't critical.

Why does Git still use SHA-1?

Git's security model doesn't rely solely on collision resistance, and the Git community is working on transitioning to SHA-256. The migration is complex due to backward compatibility requirements.

What's the difference between SHA-1 and MD5?

SHA-1 produces 160-bit hashes (40 hex characters) compared to MD5's 128-bit hashes (32 hex characters). SHA-1 is more secure than MD5 but both are deprecated for security use.

Should I migrate from SHA-1 immediately?

For security applications, yes - migrate to SHA-256 or higher immediately. For non-security uses like checksums, migration is less urgent but still recommended for future-proofing.

What should I use instead of SHA-1?

Use SHA-256 for general cryptographic purposes, SHA-512 for high security requirements, and bcrypt/Argon2 for password hashing. SHA-3 is also a good choice for new applications.

How long is a SHA-1 hash?

SHA-1 always produces a 160-bit hash, which is typically represented as a 40-character hexadecimal string (4 bits per hex character: 40 × 4 = 160 bits).

Technical Implementation

Our SHA-1 tool uses the Web Crypto API for secure hash generation:

// SHA-1 Hash Generation using Web Crypto API

async function generateSHA1(text) {

// Convert text to bytes

const encoder = new TextEncoder();

const data = encoder.encode(text);

// Generate SHA-1 hash

const hashBuffer = await crypto.subtle.digest('SHA-1', data);

// Convert to hex string

const hashArray = Array.from(new Uint8Array(hashBuffer));

return hashArray.map(b => b.toString(16).padStart(2, '0')).join('');

}

Key features of our implementation:

Uses native Web Crypto API for reliable SHA-1 generation
Proper UTF-8 text encoding handling
Real-time hash generation as you type
Hash comparison and verification functionality
Clear deprecation warnings and migration guidance