This paper introduces a novel online vocabulary profiling application called the New Word Level Checker (https://nwlc.pythonanywhere.com/) and word list resources used by the application. First, the rationale for developing another web vocabulary profiler and the word lists included in the application are described. Next, the lexical units (i.e., how words are counted) and rules (e.g., case sensitivity, contractions, abbreviations with periods, hyphenated words, and compounds) employed in the application are explained. Then, the word lists adopted for the application are compared to show which lists are best used for different purposes. Pedagogical implications of the use of the application and word lists are discussed, especially focusing on matching learners with vocabulary-level appropriate tests.