Doc martens sandals run big or small?

Hi❤️ sorry for making this post on the wrong group but I just need some help! So someone is selling some doc sandals I’m normally size 8 but these sandals are size 9! I am unsure if they would be super big…

I have doc boots and I got them in 8.5 and they fit good, but I do not know if I could fit into these sandals. If you have the doc sandals did you get your regular size? Thank you!!!