With a top-notch course delivery platform and excellent supplementary learning materials, Kaplan is the best all-around option for GRE test prep online. Kaplan's live online GRE prep course mirrors their standard on-site course, with eight live course sessions that last three hours each. As a live online student, you ask your instructor questions, participate in class discussions, take notes, and work on lecture questions in a collaborative on-screen whiteboard space. Kaplan's on-demand course provides anytime access to eight three-hour class sessions recorded in advance. Although you can't interact with an instructor in real time, you are entitled to full email support from a Kaplan instructor for the length of your on-demand course. Enrolling in either of these Kaplan online courses gets you full access to Kaplan's deep selection of learning resources, including 180 additional hours of online instruction and practice materials, seven full-length GRE practice tests, more than 5,000 example GRE questions, and much more. Get Details

The Princeton Review is a very strong alternative to Kaplan, with an excellent course delivery platform and a deep selection of practice materials and supplementary study resources. The live online course includes 24 hours of instruction that emphasizes student-instructor interaction to engage students and promote active learning. Live online students get full access to 184 hours of online resources, including the full on-demand course. As a self-paced student, you get access to the same 184 hours of archived materials, including the full on-demand course and supplementary instructional and study materials. The only difference between the live online course and the on-demand course is the 24 hours of live online class time. Both programs provide a complete set of printed learning materials, eight full-length GRE practice tests, and other resources. Get Details

PowerScore's GRE prep online course lineup doesn't include an on-demand option. However, PowerScore does offer several unique live online courses that are well worth a look. First, the company's standard live online course provides 30 hours of instruction, four full-length practice GRE tests, and solid supplementary course materials. While this course is a quality study option, PowerScore really stands out for their 15-hour focused courses. These courses provide live online instruction focused on either the quantitative reasoning section or the verbal reasoning section of the GRE. These courses make a terrific specialized study option if one of these GRE content areas is especially challenging for you. Finally, PowerScore offers a unique live online refresher course designed to provide a comprehensive overview of GRE content and strategy in 16 hours of class time. This course is held four hours per day over two consecutive weekends. Get Details

Manhattan Prep is home to another pair of excellent GRE prep online courses. As a Manhattan Prep online student, you can take a comprehensive live online course that includes 27 hours of interactive instruction. The course includes numerous hard-copy study materials, including study guides and a book of 1,800 practice questions. You also get access to a variety of online learning materials, including six practice GRE tests. If you prefer the on-demand course, you get access to an archived copy of the course lectures and all the same supplementary materials. The Manhattan Prep online course is one of the most affordable online GRE prep options in the industry. Get Details