What is a hash function?

A hash function converts data of any size into a fixed-size string of characters (the hash/digest). Same input always produces same output. Even tiny input changes produce completely different hashes (avalanche effect). One-way: cannot reverse hash to get original input.

What are common hash algorithms?

MD5: 128-bit, fast but cryptographically broken. SHA-1: 160-bit, deprecated for security. SHA-256/SHA-512: Secure, widely used. bcrypt/scrypt/Argon2: Designed for passwords, intentionally slow. SHA-3: Latest standard, Keccak-based.

What is the difference between hashing and encryption?

Hashing is one-way—you cannot get the original data back from a hash. Encryption is two-way—encrypted data can be decrypted with the key. Use hashing for passwords (verify without storing), encryption for data that needs to be retrieved.

How are hashes used for passwords?

Passwords are hashed before storage. To verify, hash the input and compare hashes. Use salt (random data added before hashing) to prevent rainbow table attacks. Use slow algorithms (bcrypt, Argon2) to resist brute force. Never store plain-text passwords.

What is a hash collision?

A collision occurs when two different inputs produce the same hash. All hash functions have potential collisions (infinite inputs, finite outputs), but good algorithms make finding them computationally infeasible. MD5 and SHA-1 have known collision vulnerabilities.

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Hash Generator

Hash functions convert data to fixed-size strings. SHA-256 produces 64 hex characters. MD5 produces 32 hex characters (deprecated for security). Same input always produces same hash. Hashing is one-way—cannot reverse to get original.

Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes. Compare hash security levels and copy results.

Enter Text

About Hash Functions

MD5: Fast but cryptographically broken. Use only for checksums.
SHA-1: Also deprecated for security. Avoid for new applications.
SHA-256: Secure and widely used. Good default choice.
SHA-384/512: Higher security for sensitive applications.

Common Uses

File integrity verification (checksums)
Password storage (with salt)
Digital signatures
Data deduplication

How to Use

Enter your value in the input field
Click the Calculate/Convert button
Copy the result to your clipboard

Frequently Asked Questions

What is a hash function?: A hash function converts data of any size into a fixed-size string of characters (the hash/digest). Same input always produces same output. Even tiny input changes produce completely different hashes (avalanche effect). One-way: cannot reverse hash to get original input.
What are common hash algorithms?: MD5: 128-bit, fast but cryptographically broken. SHA-1: 160-bit, deprecated for security. SHA-256/SHA-512: Secure, widely used. bcrypt/scrypt/Argon2: Designed for passwords, intentionally slow. SHA-3: Latest standard, Keccak-based.
What is the difference between hashing and encryption?: Hashing is one-way—you cannot get the original data back from a hash. Encryption is two-way—encrypted data can be decrypted with the key. Use hashing for passwords (verify without storing), encryption for data that needs to be retrieved.
How are hashes used for passwords?: Passwords are hashed before storage. To verify, hash the input and compare hashes. Use salt (random data added before hashing) to prevent rainbow table attacks. Use slow algorithms (bcrypt, Argon2) to resist brute force. Never store plain-text passwords.
What is a hash collision?: A collision occurs when two different inputs produce the same hash. All hash functions have potential collisions (infinite inputs, finite outputs), but good algorithms make finding them computationally infeasible. MD5 and SHA-1 have known collision vulnerabilities.