Join tool not matching what appears to be the same data

[arianner]

I'm trying to match 2 sets of data together based on a few conditions and I am getting matches, but I can also see lines from the right and left sides that appear to be identical (and pasting them in excel shows them to be true to eachother) but aren't getting picked up by the match. Any ideas on why this can be?

[DataNath]

@arianner are you able to show a screenshot/paste a sample of these lines (in both sources)? The Join tool will stitch identical rows together if the keys are the same so if they look the same it may be something subtle like excess whitespace in one side, a slight mismatch in capitalisation (Alteryx is case-sensitive) etc.