Manual SameSite Cookie Test
Manually test the behaviour of SameSite cookies in your browser across the different cross-site request types:
POST, and embedded content.
Automatic SameSite Browser Test
Automated test suite that audits the behaviour of your browser with the different SameSite options, across https and http, same-site and cross-site requests. Note, it will take a while as there is a delay of 2 minutes to properly account for
SameSite=Lax+POST in Chrome.
An experiment by Stephen Rees-Carter for "CSRF is dead (or is it?)" and "SameSite Cookies Deep Dive".
Source Code on GitHub, PRs welcome.