It was replaced by Sha2 (224, 256, 384 and 512 bits), and more recently by Sha-3. Like Md5, Sha-1 is an unilateral function, to decrypt the plaintext behind a hash, you have to confront it to a online sha1 database. This website allows you to compare your Sha1 hashes and decrypt it online if you're lucky, thanks to our efficient online database.