What is a Hash Function?
A cryptographic hash function takes an input of any size and produces a fixed-length output called a hash or digest. The same input always produces the same hash, but even a tiny change in the input completely changes the output. Hash functions are one-way — you cannot reverse a hash back to the original text.
SHA Algorithms Compared
SHA-1 (160-bit digest) — Legacy — avoid for security purposes, broken for collision resistance.
SHA-256 (256-bit digest) — Most widely used. Secure, fast, standard choice for most applications.
SHA-384 (384-bit digest) — Part of SHA-2 family. More secure than SHA-256 with a larger digest.
SHA-512 (512-bit digest) — Strongest SHA-2 variant. Preferred for high-security applications.
Common Use Cases
- Verifying file integrity (checksums)
- Storing password hashes (with a proper KDF like bcrypt on the server)
- Data deduplication
- Digital signatures and certificates
- Content-addressable storage
Is this tool private?
Yes. Hashing is computed entirely in your browser using the crypto.subtle.digest() Web Crypto API. Your text is never sent to a server.