EVP Text Inspector allows you to see a lexical profile of a text. The word limit is 500 words, and you simply paste (or type) the text into the search box and then run the workflow.
You'll then see a list of words at each level (A1, A2, B1, B2, C1 & C2), plus any unlisted words. These may be misspellings, proper names, more unusual words etc.
You also see the entire text highlighted word by word according to the word's level (A1, A2 etc).
I've made a short video to show you how to use EVP Text Inspector. Click on the play arrow to start: you can enter full screen mode at the bottom right.