I struggled in the past to find JLPT past papers / mock exams without buying textbooks, so here are a few of what I found through years :
Websites : https://nihonez.com/jlpt-test/ https://japanese.todaiinews.co... (requires to sign in for free, to have access to 2 full exams (with correction and timer) from N5 to N1)
Textbooks : 合格できる日本語能力試験 : especially N5 - N4 textbook, for mock exams.
新日本語５００問 : small-sized textbook (quite thick though), from N5 to N1 (N5 and N4 together), 3 questions on each page (1 kanji, 1 vocabulary, 1 grammar), answers and translations at the back, very good to do a few questions every day when a full-fledged exam seems too difficult.
I'd be happy if others people posted below what they use / found for reference !
