まで・さえ: the difference
までN4
Meaning
Even, To even, To the extent of
Past papers
Tested 3 times in past papers
Example
こっちまでイライラしてきた。
Now even I'm starting to get annoyed.
さえN3
Meaning
Even
Past papers
Tested 2 times in past papers
Example
富士山の頂上は夏でさえ寒い。
It is cold on the summit of Mt. Fuji even in summer.
How to tell them apart
This is not the 「まで」 of 'until': 「5時まで働く」 means 'work until 5'.
「さえ」 names the bare minimum, usually with a negative: 「ひらがなさえ読めない」 (can't even read hiragana).
「でも」 names an easy example: 「子供でもわかる」 (even a child understands).