Grammar & Spelling Check; Free Online Proofreading; No Downloads...Allows you to find those pesky mistakes and correct them before your teacher does...
Jim Lerman's insight:
I checked this out for something I had just written. It is way, way better than the checker built into Microsoft Word. PaperRater offers not only spelling and grammar check, but also plagiarism detection, and suggestions for improving writing. The service is free and fast. I plan to use it for myself as well as recommending it to colleagues and students.
Via Jim Lerman