At the risk of stating the obvious, if you want your character class (the stuff inside the square brackets) to match a space, you should include a space in your character class. If you want only a space (that is, not other space-like characters like tabs) something like this should work: .*TEXT:.*?([a-zA-Z0-9_\x7f-\xff.\w ]+)". This is your regex with a space inserted before the right square bracket. If you want all the space-like stuff, use \s instead of a literal space.

You did not ask about this, but I observe that your character class appears to contain unneeded information. I am not aware of any circumstance where \w does not include ranges a-z, A-Z, 0-9, and the underscore (_). Certainly it does under ASCII, the ISO encodings, CP1252, and Unicode. So you should find that .*TEXT:.*?([\x7f-\xff.\w ]+)" matches everything you want, and is easier to understand.