The resources below are ranked for their overall value to educators teaching math online. The ranking considers instructional quality, strength of evidence, usefulness for teachers, accessibility, breadth, and how well each resource supports student reasoning. No single option is best for every classroom; grade level, instructional purpose, student needs, and budget still matter.
1. Khan Academy
Khan Academy offers one of the broadest free collections of math instruction and practice available, spanning early math through calculus, statistics, and college-level topics. Teachers can assign lessons and practice, monitor progress, identify unfinished learning, and use course-mastery tools to support self-paced learning.
Best for: Free, comprehensive instruction, practice, differentiation, and progress monitoring across grade levels.
2. Zearn Math
Zearn is a nonprofit K–8 math platform combining interactive digital lessons, visual models, fluency practice, feedback, and paper-and-pencil problem solving. Its evidence base includes a large independent randomized study, earning it a “Strong” Tier 1 rating from Evidence for ESSA.
Best for: Evidence-based K–8 core instruction, intervention, tutoring, and differentiated grade-level practice.
3. Brilliant
Brilliant is an interactive math and coding platform built around active problem solving for learners from about grade 5 through college. Its AI tutor, Koji, asks guiding questions and can annotate the problem on screen when students get stuck rather than simply providing the answer.
Best for: Visual problem solving, conceptual understanding, independent learning, enrichment, and guided support when students get stuck.
4. Amplify Classroom
Formerly known as Desmos Classroom, Amplify Classroom provides interactive K–12 activities that help students explore mathematical relationships, explain their reasoning, compare approaches, and respond to teacher feedback. Its strongest activities make student thinking visible rather than reducing math to answer entry.
Best for: Interactive lessons, mathematical discussion, formative assessment, and making student reasoning visible.
5. Illustrative Mathematics
Illustrative Mathematics provides a coherent, standards-aligned K–12 curriculum centered on problem solving, mathematical discourse, conceptual understanding, and student-generated strategies. Its lessons are especially useful for teachers who want students to learn mathematics by doing and discussing mathematics.
Best for: Problem-based core instruction, mathematical discourse, lesson planning, and standards-aligned curriculum.
6. GeoGebra
GeoGebra combines graphing, geometry, algebra, statistics, calculus, 3D modeling, interactive activities, and collaborative classroom tools. Its open-ended design allows students to manipulate mathematical objects and investigate relationships instead of only completing predetermined exercises.
Best for: Dynamic visualization, mathematical modeling, geometry, algebra, calculus, and student investigation.
7. PhET Interactive Simulations
Developed at the University of Colorado Boulder, PhET provides free, research-informed simulations for mathematics and science. Students manipulate variables, test ideas, and observe mathematical consequences in visual environments designed for exploration and discovery.
Best for: Concept exploration, inquiry, visual models, interdisciplinary STEM learning, and accessible simulations.
8. ST Math
ST Math is a PreK–8 visual instructional program that minimizes language demands and asks students to reason spatially through mathematical puzzles. Its design can be especially valuable for multilingual learners and students who benefit from nonverbal representations before formal notation is introduced.
Best for: Visual reasoning, conceptual development, multilingual learners, intervention, and elementary or middle-school practice.
9. DeltaMath
DeltaMath gives middle- and high-school teachers a large library of assignable problem types, immediate feedback, instructional supports, and detailed performance data. It is particularly useful for targeted practice, although teachers should pair procedural work with discussion, modeling, and richer problem solving.
Best for: Secondary math assignments, targeted practice, feedback, assessment, and progress monitoring.
10. IXL Math
IXL provides extensive standards-aligned skill practice, adaptive question difficulty, diagnostics, recommendations, and teacher reporting across K–12 mathematics. Its breadth makes it useful for identifying and practicing specific skills, but it is strongest when used alongside richer instruction rather than as the entire learning experience.
Best for: Diagnostics, standards-aligned skill practice, differentiation, review, and progress monitoring.
11. Mathigon Polypad
Polypad is a flexible collection of virtual manipulatives for exploring numbers, fractions, algebra, geometry, probability, and data. Teachers and students can combine tiles, shapes, number bars, graphs, and other objects on a shared mathematical canvas.
Best for: Virtual manipulatives, visual explanations, student modeling, demonstrations, and exploratory tasks.
12. OpenStax
OpenStax, based at Rice University, publishes free, peer-reviewed, openly licensed textbooks for algebra, precalculus, calculus, statistics, and other college-level subjects. Its materials are less interactive than most resources on this list but provide substantial, dependable course content without textbook costs.
Best for: Free secondary and college textbooks, readings, examples, problem sets, and complete course materials.
13. Art of Problem Solving
Art of Problem Solving offers rigorous courses, textbooks, videos, and interactive challenges for students ready for advanced mathematics. Its emphasis on reasoning and nonroutine problems is excellent, but its difficulty and specialized focus make it less suitable as a general classroom resource.
Best for: Advanced learners, mathematical reasoning, competition preparation, and challenging enrichment.
14. WolframAlpha
WolframAlpha is a powerful computational engine for algebra, calculus, statistics, differential equations, and other advanced topics. It can support verification, visualization, and analysis, but teachers should design its use carefully so students interpret results and explain reasoning rather than simply retrieve solutions.
Best for: Advanced computation, checking work, mathematical modeling, visualization, and higher education.
15. Youcubed
Youcubed provides open-ended “low-floor, high-ceiling” tasks, instructional ideas, and professional-learning resources intended to encourage multiple strategies and productive mathematical discussion. It is more of a teaching-resource collection than a complete online-learning platform.
Best for: Rich tasks, mathematical discussion, multiple solution strategies, mindset, and teacher planning.
16. Brighterly
Brighterly provides paid one-to-one online tutoring in mathematics, including diagnostic assessment, individualized lessons, and parent progress reporting. Direct tutoring may be valuable for families seeking sustained personal support, but its narrower use case, cost, and limited whole-class utility place it below the broader classroom resources above.
Best for: Families seeking recurring one-to-one online math tutoring and individualized support.