Hash Generator: Generate Cryptographic Hashes Online

Create cryptographic hashes for text or files with our free online hash generator. A hash is like a unique digital fingerprint for your data—it takes any input (text, file, password) and converts it into a fixed-length string of characters. Even a tiny change in the input creates a completely different hash. This makes hashes perfect for verifying file integrity, checking if downloads are safe, and comparing data without revealing the original content.

Choose from multiple hash algorithms: MD5, SHA-1, SHA-256, or SHA-512. Enter text directly or upload a file to generate its hash instantly. See all hash values at once for easy comparison. Perfect for verifying file checksums, testing data integrity, or generating unique identifiers. All hashing happens locally in your browser using native Web Crypto API—your data never leaves your device.

Generated Hashes

SHA-256

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SHA-512

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SHA-1 (Deprecated)

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MD5 (Deprecated)

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What are Cryptographic Hashes?

A cryptographic hash function takes an input (or 'message') and returns a fixed-size string of bytes. The hash is designed to be a one-way function - it's practically impossible to reverse the process to get the original input from the hash output.

Common Use Cases:

  • File integrity verification (checksums)
  • Password storage (with salt)
  • Digital signatures
  • Git commit IDs (SHA-1)
  • Data deduplication
  • Blockchain and cryptocurrencies

Hash Algorithms:

SHA-256 (Recommended):

  • 256-bit hash (64 hexadecimal characters)
  • Part of the SHA-2 family
  • Cryptographically secure
  • Used in Bitcoin, SSL/TLS certificates
  • Best choice for most applications

SHA-512 (Most Secure):

  • 512-bit hash (128 hexadecimal characters)
  • Part of the SHA-2 family
  • More secure than SHA-256
  • Slower but provides higher security margin

SHA-1 (Deprecated):

  • 160-bit hash (40 hexadecimal characters)
  • Not recommended for security purposes
  • Collision attacks have been demonstrated
  • Still used in Git for commit IDs

MD5 (Deprecated):

  • 128-bit hash (32 hexadecimal characters)
  • Not recommended for security purposes
  • Vulnerable to collision attacks
  • Still used for checksums and non-security applications

Hash Properties:

  • Deterministic: Same input always produces same hash
  • One-way: Cannot reverse hash to get original input
  • Fast to compute: Quick to generate hash from input
  • Avalanche effect: Small change in input drastically changes hash
  • Collision resistant: Hard to find two inputs with same hash

Example:

Input:

Hello, World!

SHA-256 Hash:

dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f

Features:

  • Support for MD5, SHA-1, SHA-256, and SHA-512
  • Text and file hashing
  • Real-time hash generation as you type
  • One-click copy for each hash
  • 100% client-side - your data never leaves your browser

Important Security Notes:

  • Never use for passwords directly: Always add salt and use key derivation functions (bcrypt, scrypt, Argon2)
  • Avoid MD5 and SHA-1 for security: Use SHA-256 or SHA-512 instead
  • Hashes are not encryption: They cannot be decrypted to get original data

Frequently Asked Questions

What is a hash and what is it used for? +

A hash is a fixed-size string generated from any input data using a mathematical algorithm. It's like a unique fingerprint—the same input always produces the same hash, but different inputs produce different hashes. Hashes are used for password storage, file integrity verification, digital signatures, and data deduplication.

Which hash algorithm should I use? +

For security purposes (passwords, digital signatures), use SHA-256 or SHA-512. For file checksums and integrity verification, SHA-256 is the standard. MD5 and SHA-1 are considered cryptographically broken and should only be used for non-security purposes like checksums of trusted files.

Can I reverse a hash to get the original data? +

No, cryptographic hashes are one-way functions by design. You cannot mathematically reverse a hash. However, weak passwords can be cracked using rainbow tables or brute force by trying many inputs until one matches. This is why strong, unique passwords and salted hashes are essential.

Why do small changes produce completely different hashes? +

This is called the avalanche effect—a key property of good hash functions. Changing even one character completely changes the hash output. This makes hashes useful for detecting any modification to data, as even tiny changes are immediately obvious.

What's the difference between MD5, SHA-1, SHA-256, and SHA-512? +

These differ in output size and security: MD5 produces 128-bit hashes (32 hex chars), SHA-1 produces 160-bit (40 chars), SHA-256 produces 256-bit (64 chars), and SHA-512 produces 512-bit (128 chars). Larger hashes are more secure but slower. SHA-256 offers the best balance for most uses.