Plugging Content Holes and Extra Practice
Math
https://academy.act.org/ - This is my favorite free site for reviewing basic math concepts. If I could only recommend one site, this would be it. ~Kim
https://www.ixl.com/math/geometry - covers all types of math and has practice problems
English
https://www.ixl.com/ela/grade-10
https://www.ixl.com/ela/grade-11
https://www.highschooltestprep.com/act/english/
Reading
https://www.testprepreview.com/modules/reading1.htm
https://www.testprepreview.com/modules/reading3.htm
https://academy.act.org/ - This is my favorite free site for reviewing basic math concepts. If I could only recommend one site, this would be it. ~Kim
https://www.ixl.com/math/geometry - covers all types of math and has practice problems
English
https://www.ixl.com/ela/grade-10
https://www.ixl.com/ela/grade-11
https://www.highschooltestprep.com/act/english/
Reading
https://www.testprepreview.com/modules/reading1.htm
https://www.testprepreview.com/modules/reading3.htm
Websites with Free Practice Materials
CrackACT.com - outstanding site with a remarkable amount of free practice materials
ACT.org - scroll to the bottom of the page for the free test prep academy
ACT.org - scroll to the bottom of the page for the free test prep academy
Books We've Written
Our Free Study Materials
ACT Brochures with Free Practice Tests Inside
Each year ACT publishes a brochure with a free practice test inside. The same test is reused for a year or two, so this list doesn't include years with duplicate tests.