Text Inspector is an online tool that analyzes texts and benchmarks them to the Common European Framework of Reference for Languages (CEFR). It provides detailed metrics on 16 variables related to a text's readability, lexical sophistication, and other features. While a valuable resource, Text Inspector is not intended as a complete automated marking system and still requires human judgment. The tool is based on extensive research and frequency data from corpora. It allows teachers to select appropriate texts for students and to better understand why some texts may be more difficult than others.