While merely registering for the GMAT costs $250, there’s no reason to spend half of your bank account on GMAT prep materials. There are plenty of free resources available to GMAT test-takers.

In no particular order, here are the 21 best free GMAT prep resources:

Official GMAT Software- 90 free questions with explanations, plus two full-length free practice tests.

Beat the GMAT Forums-Extensive GMAT resources and discussion forums. The Beat the GMAT site is an especially good source for practice questions.

GMAT Club Forums-Slightly more active discussion forums than Beat the GMAT, and arguably with more experts posting. Extensive “toolbox” of prep materials.

Veritas Prep GMAT Simulator-allows you to take a practice GMAT test under test-like conditions, and includes a Verbal section, a Quantitative section, and an Analytical Writing Assessment.

GMAT Club Practice Tests-The first 2 tests are free to anyone who signs up for GMAT Club. The other 18 tests are available at cost or for free to any member with 25 “Kudos.” They’re also free on US public holidays. These tests are relatively challenging and especially useful for Quant.

Kaplan Practice Test-Offers the same free practice test in two different formats. Test-takers can take the test as part of a live online event, and have the opportunity to ask questions of an instructor and participate in a live chat. You can also take the same practice test on your own time as a “self-protoctered” exam.

Economist Practice Test and Questions-The Economist allows you to sign up for a 7-day free trial, enough time to take their free practice test and browse some of their sample questions.

GMAT Pill Practice Test- One of the only free practice tests to allow you to pause the test and resume another time. Also allows you to compare your question timing to other users.

Manhattan GMAT Practice Test-Another full-length practice test, and generally one of the more realistic. The test allows you to set time limits by section or question.

Veritas Question Bank-Made up of recently written questions that will eventually find their way into Veritas’ paid content. Most of the questions are realistic, but some are obviously in the early stages.

Assorted GMAT Blogs- Most GMAT prep companies post study tips and practice questions on their blogs. We’ve linked to Beat the GMAT’s blog feed (which includes posts from many of the big prep companies), but there are plenty of GMAT blogs available, including the official GMAT blog.

Manhattan GMAT Flashcards-100+ downloadable and printable concept flashcards, all created by Manahattan GMAT tutors.

Beat The GMAT Flashcards-300 subject and strategy-based flashcards. All of these are created by users, but they’re relatively high quality.

GMAT Club Downloads-Hundreds of resources to help keep your study process organized, from flashcards to an error log.

GMATPrepNow Video Series-Over 100 free subject-based GMAT videos. Especially useful for those looking to improve Quant.

Khan Academy Lessons-Great for brushing up on fundamental quant concepts, though not always helpful for more advanced quant students.

Veritas Prep Videos-Offers more structured lessons and general strategy tips, though not all of the videos are free.

Magoosh’s “Complete Guide to the GMAT” eBook-Comprehensive GMAT prep guide, as well as a second eBook specifically for Integrated Reasoning.

Manhattan’s “GMAT Uncovered” eBook-Includes an extensive discussion of GMAT strategy as well as practice questions and explainations.

GMAT Pill’s “How to Ace the GMAT in One Month” eBook-Heavy on general GMAT strategy, though still a good resource for concepts and practice questions.

Prep4GMAT App-This list wouldn’t be complete without mentioning the free Prep4GMAT app, which has over 1000+ questions and concept flashcards, and is free for a limited time.