This short English test gives you a score of A, B or C on the CEFR scale for receptive English skills (listening and reading). The test is called the EFSET Express. There's a longer version that gives you a more precise score that you can publish straight to your LinkedIn profile for job hunting purposes. If you're really looking for a challenge, the 2 hour EFSET Plus tells you what you'd score on the TOEFL and IELTS. It's a great way to prepare for a standarized English test. All three English tests are available at no charge on the official EFSET site.
When you're looking for an English test, it's better to choose a test that evaluates English in context, rather than just testing your mastery of English grammar rules. The EFSET tests are exactly this type of practical English test. They evaluate how well you use English, making sure you can apply grammar rules, that you have a good English vocabulary, and that you can use your knowledge to communicate in English. Free is also nice.