If third-party cookies are blocked you will only see one cookie in the Site B iframe:
If third-party cookies are allowed you will see two cookies in the Site B iframe:
Test the behavior with third-party cookies blocked
- Use Chrome 118 or higher.
- Set the
chrome://flags/#test-third-party-cookie-phaseoutflag and restart Chrome.
- When you load this page, you should only see one cookie in the Site B iframe.
- Click Go to Site B
When you are on Site B the unparitioned cookie is not in third-party context so it's not blocked and you will see two cookies:
Clear cookiesTo reset the demo, clear all cookies for the site:
- In Application > Storage > Cookies >
- Right click on
- Click Clear