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SHA-256 & MD5 Hash Calculator

Calculate SHA-256, MD5, and other hash digests online

Tip: All calculations are processed locally in your browser, data is never uploaded to any server

About This Tool

Hash is an algorithm that converts arbitrary length data into a fixed-length digest. The same input always produces the same output, but the output cannot be reversed to get the input, and small input changes cause completely different outputs. This tool supports common hash algorithms including MD5, SHA-1, SHA-256, and SHA-512 for quickly calculating text hash values. All calculations are processed locally in your browser - your data is never uploaded to any server, making it safe for sensitive information.

How to Use

  1. Enter or paste the content you want to hash in the 'Input Text' box
  2. Click 'Calculate Hash' button
  3. Select an algorithm (SHA-256 is selected by default)
  4. Click Calculate, then Copy the highlighted digest — switch algorithms anytime
  5. You can verify data integrity by comparing hash values

Common Use Cases

  • File verification: Calculate file hash values to verify download integrity
  • Password storage: Use hash to store passwords (recommended with salt)
  • Data integrity: Verify data hasn't been tampered during transmission
  • Digital signatures: As foundation for digital signatures and certificates
  • Data deduplication: Use hash values to quickly determine if data is duplicate
  • Blockchain: Hash algorithms are core to blockchain technology

FAQ

Q1: What's the difference between MD5, SHA-1, and SHA-256?

Main differences are output length and security: MD5 produces 128-bit (32 hex characters) hash, SHA-1 produces 160-bit (40 characters), SHA-256 produces 256-bit (64 characters), SHA-512 produces 512-bit (128 characters). MD5 and SHA-1 are no longer considered secure, SHA-256 or higher is recommended.

Q2: Can hashes be cracked?

Hashes are one-way, theoretically impossible to reverse to original text. However, MD5 and SHA-1 have been found to have collision vulnerabilities (different inputs producing same hash), should not be used for security-sensitive scenarios. Simple passwords may be attacked by rainbow tables, so password storage should use specialized algorithms like bcrypt or scrypt.

Q3: Why is the hash value different for the same content?

Possible reasons: 1) Invisible spaces or newlines before/after text; 2) Different character encodings used (UTF-8 vs GBK); 3) Different line endings between Windows and Unix (CRLF vs LF). Hash is extremely sensitive to input - any tiny difference results in completely different output.

Q4: Can this tool calculate file hashes?

Currently this tool only supports text input. File hash calculation requires reading the entire file content, which may affect browser performance for large files. For file hashes, you can use command-line tools like md5sum, sha256sum, or professional file verification software.

Q5: What's the difference between hash and encryption?

Hash is one-way and cannot restore original text; encryption is two-way and can be decrypted to restore. Hash is used to verify data integrity, encryption is used to protect data confidentiality. For example, passwords should be hashed for storage not encrypted, because hash cannot be reversed.

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