Factors such as length of document, subject matter complexity, language quality and turnaround time will all impact the cost of a professional proofreader. A short essay will cost less than a long dissertation, and urgent deadlines might be a factor in the price. If comparing prices for Online proofreading services, ensure that students read whether the price quoted includes grammar editing only or grammar, formatting, and referencing editing. Get a definite quote before taking the service, and consider other factors besides price. There are those that offer by-the-word and hourly rates, as well as those that have a fixed charge. Be sure to verify a final price before purchase.