Generate MD5, SHA-1, SHA-256 and SHA-512 hashes of any text, right in your browser.
No. MD5 and SHA-1 are cryptographically broken — collisions can be generated in practice — so don't use them for passwords or signatures. SHA-256 or SHA-512 are the right choice for anything security-sensitive; MD5/SHA-1 are still fine for checksums and non-security data integrity checks.
No. SHA hashes are computed with your browser's built-in Web Crypto API, and MD5 runs via a local JavaScript implementation. Nothing you type is sent to a server.