Grammarlookup is a grammar and punctuation checker, based on the languagetool.org software it can detect many contextual errors, it can also suggest the style. Simply enter the text that you want to check for grammar and click the lookup button, you will see many errors underlined in which the red underlined are the spelling ones, the blue ones are the grammar and the green ones are the style that you can ignore in many cases. The deep lookup button uses Grammarly API to give you a report for advanced grammar and punctuation suggestions. Bookmark the page for the later use.