Hash Generator (SHA-256, SHA-512)

No, SHA-256 is not reversible. It is a one-way function, so there is no way to calculate the original text from the hash. People can only guess inputs and compare hashes, which works for short or common text. That is why weak passwords can still be found through lookup tables and guessing.

The main difference is output length and security. SHA-1 gives a 160-bit hash and is considered broken for security because collisions have been found. SHA-256 gives 256 bits and SHA-512 gives 512 bits; both are part of SHA-2 and are secure today. SHA-256 is the most widely used choice.

SHA-1 is not safe for security uses such as digital signatures or certificates. Researchers showed a practical collision in 2017, meaning two different files can share one SHA-1 hash. It is still used for non-security tasks, like identifying objects in Git or checking files for accidental changes.

No, plain SHA-256 is not a good way to store passwords because it is very fast, which makes guessing attacks easy. Use a slow password hashing algorithm made for this job, such as bcrypt, scrypt, or Argon2, with a unique salt for each password. SHA-256 is better for file checks and signatures.

The same text always gives the same hash because hash functions are deterministic. This lets you check that a file or message has not changed: compare its hash with the expected value. Even one different character, space, or capital letter creates a completely different hash, so input must match exactly.