This online tool allows you to generate the SHA256 hash with a SALT of any string. SHA256 is designed by NSA, it's more reliable than SHA1. With the GDPR you have to pseudonymize personally identifiable information (PII), or sensitive personal information (SPI), you are processing. With this tool you can hash + salt your PII for giving it to your subprocessors without the need of a DPA (maybe, please check for other reasons).
the hash rule is: hash= SHA256(SALT(STRING)+STRING).
please mind that STRING is case sensitive!

Try also the GDPR SHA256 + MD5-SALT Hash generator online for lists to pseudonymize (aka pseudonomize) PII.

This online generator is safe because the magic only happens in your browser and not on a server!
If you like it, please buy me a beer -> here