The passwds.ninja Chrome extension, including the password generation javascript. All password generation happens in the browser.
The extension can be installed from https://chrome.google.com/webstore/detail/passwds-ninja/pjeobohajbopobondedhdnljhmoifncf
This extension also has a sibling website, found at https://passwds.ninja, whose source can be found at https://github.com/allixsenos/passwds-ninja-web