[loloquwowndueo]

I use this one https://sptest.iamshowcase.com/

(Well, used : in luckily no longer in charge of an IdP with a bespoke SAML implementation so I don’t need to deal with this crap anymore!)

[ucarion]

FWIW back in the day, samltest.id was a dummy IDP, whereas sptest.iamshowcase.com is a dummy SP. You could hook these two up to each other and see the whole flow.