What is a hash and why would I use it?▼
A hash is a fixed-length string generated from input data using a mathematical algorithm. It's used for data integrity verification, password storage, digital signatures, and checksums to verify file downloads.
Which hash algorithm should I use?▼
For security purposes, use SHA-256 or SHA-512. MD5 and SHA-1 are considered cryptographically broken for security but are still useful for checksums and non-security purposes like cache keys.
Can a hash be reversed?▼
No. Cryptographic hash functions are one-way — you cannot recover the original input from a hash. This is what makes them useful for password storage. Each unique input produces a unique hash.