A hash function converts input data into a fixed-size string of characters. It is one-way, meaning you cannot reverse it to get the original input.

For security, use SHA-256 or SHA-512. MD5 and SHA-1 are considered cryptographically broken and should only be used for checksums, not security.

Hashing is one-way, but for passwords you should use specialized password hashing algorithms like bcrypt, Argon2, or scrypt in production applications.

SHA-256 produces a 256-bit hash (64 hex characters) while SHA-512 produces a 512-bit hash (128 hex characters). SHA-512 is faster on 64-bit systems but SHA-256 is more widely compatible.

Yes, you can paste the file contents or text into the input field to generate a hash. For large files, consider using command-line tools instead.