Check that a site's HTTPS certificate is valid and not about to expire, create strong passwords, see how a password would hold up against guessing, and generate hashes.
| I want to… | Use |
|---|---|
| Find out when a site's certificate expires, or why browsers show a certificate warning | SSL Certificate Checker |
| Create a new random password | Password Generator |
| Check whether a password is weak or has appeared in a data breach | Password Strength Checker |
| Get the MD5 or SHA-256 hash of some text | Hash Generator |
| Check who a domain is registered to before trusting it | WHOIS Lookup |
A hash is a one-way fingerprint of data: you can't turn it back into the original. MD5 and SHA-1 are fine for checksums but are broken for security uses such as signatures. Passwords should never be stored as a plain MD5 or SHA hash; use a slow password-hashing function such as Argon2, bcrypt or scrypt.