Hash Generator

About the Hash Generator

A cryptographic hash function takes any input (text, a file, a password) and produces a fixed-length output called a hash or digest. Hash functions are one-way: it is computationally infeasible to reverse a hash back to its original input. Even a tiny change in input produces a completely different hash — a property known as the avalanche effect.

Hash algorithm comparison

• MD5 (128-bit) — Fast, but cryptographically broken. Known collision vulnerabilities mean two different inputs can produce the same hash. Not suitable for security purposes, but still used for non-security checksums and file fingerprinting.
• SHA-1 (160-bit) — Also deprecated for security use since 2017 due to demonstrated collision attacks (SHAttered). Avoid for signatures, certificates, or password storage.
• SHA-256 (256-bit) — Part of the SHA-2 family. Widely used and currently considered secure. Used in TLS, code signing, Bitcoin, and most modern security applications.
• SHA-512 (512-bit) — Also SHA-2 family. Provides a larger digest and is faster than SHA-256 on 64-bit platforms for large inputs.

Common use cases

• File integrity verification — Publishing a SHA-256 hash alongside a download lets users verify the file hasn't been tampered with.
• Data deduplication — Identifying duplicate files or data blocks by comparing hashes.
• Digital signatures — Signing the hash of a document is faster than signing the document itself.
• Checksums in APIs — Verifying payloads haven't been altered in transit.

Hashing vs encryption

Hashing is one-way and cannot be reversed. Encryption is two-way — data can be decrypted back to plaintext with the right key. Use hashing to verify integrity; use encryption to protect confidentiality. Never "hash" passwords with MD5 or SHA — use a proper password hashing function like bcrypt instead.