"Language level" is not a good metric. This comes up from time to time, with one site or another analysing your "writing level", frequently by re-purposing Flesch–Kincaid readability tests[1]. These tests tell you how hard it is to read something, and the assumption then is that my writing is better than yours because mine is "11th grade" and yours is "8th grade". Of course, having higher entry requirements does not mean my writing is in any way better, and may actually mean the converse - if you had written, for example, an accurate account of quantum physics that was accessible to 8th graders, that would be an impressive writing accomplishment indeed! An example of a site that would be unfairly penalised by measuring language level would be the simple English Wikipedia[2].

[1]: http://en.wikipedia.org/wiki/Flesch%E2%80%93Kincaid_readabil...

[2]: http://simple.wikipedia.org/wiki/Main_Page