Some grammar and vocabulary revision sites

AI to B2+

https://agendaweb.org/grammar-exercises.html

https://agendaweb.org/grammar-exercises-2.html

https://agendaweb.org/grammar/tests-quizzes3.html

https://agendaweb.org/grammar/tests-quizzes4.html

https://agendaweb.org/grammar/tests.html

B1 and B2

http://www.english-practice.at/ Great! Scroll down and look at the huge list of links!

B1 level

http://www.english-practice.at/b1/grammar/b1-grammar-index.htm

https://elt.oup.com/student/practicegrammar/advanced/a_testzone/?cc=it&selLanguage=it

B2 level

http://www.english-practice.at/b2/grammar/b2-grammar-index.htm

C1 level

https://agendaweb.org/vocabulary/tests-advanced-vocabulary3.html

https://www.examenglish.com/CEFR/C1.htm

https://www.esl-lounge.com/student/advanced.php

https://www.ihbristol.com/free-english-exercises/grammar-vocabulary-phrases/basic-verb-tenses

https://www.flo-joe.co.uk/cae/students/tests/

https://www.englishrevealed.co.uk/cae.php

https://learnenglishteens.britishcouncil.org/grammar

https://learnenglishteens.britishcouncil.org/vocabulary

https://www.examenglish.com/CEFR/C1.htm

https://learnenglish.britishcouncil.org/grammar/c1-grammar

https://englishpracticetest.net/practice-english-grammar-tests-for-c1-with-answer/

(60 free tests with answers)

All levels

https://www.english-grammar.at/index.htm  there are grammar and vocabulary links on the right of the page and others as you scroll down