If you use any of the better password managers this feature exists and runs automatically. If you don't want to go that route, then you can make use of https://haveibeenpwned.com/

Thank you, I've edited my comment to be more specified

I have a gmail account which google one shows, it along with a username has been leaked on dark web, but haveibeenpwned shows email was not found in any data breach. How is that possible?

They're using different data sources.

Services already exist that does this. Some password managers will check but the popular service often talked about on here is https://haveibeenpwned.com/

Thank you, I've edited my comment to be more specified

They used to publish a torrent with hashes, but then went full SaaS.

Download Have I Been Pwnds dataset then: https://github.com/HaveIBeenPwned/PwnedPasswordsDownloader

HIBP lets you download their hashed passwords DB to check against.

https://github.com/HaveIBeenPwned/PwnedPasswordsDownloader

I agree - download all the passwords and don't single out what you're checkign for someone else to see.

I don't know why we can't use this kind of thing for better privacy everywhere.

A similar example (outside the realm of passwords) would be when checking for a software update. Instead of sending "i have software xyz version 1.2.3", just download a current list of software and check it locally against your software. Probably would be faster anyway to download a static dataset instead of hitting a remote database.

Each time a breach like this happens I want to download the file and check if;

1. People on my s*t list are in the dataset, and

2. Any of their passwords are in that dataset.

Then I can use the information to make their lives miserable.