There's no shortage of math apps. There is a shortage of honest comparisons.
Khan Academy remains the gold standard for free math education. Its video library is comprehensive, the exercises are solid, and it covers everything from elementary arithmetic to university-level calculus. The limitation is format: video-based learning creates recognition without necessarily building recall. There's also no long-term retention system — once you've worked through a topic, nothing brings it back. Best for: supplementing a course, looking up specific concepts, or accessing free content with no budget.
Brilliant teaches through interactive problem-solving. Instead of explaining a concept then testing it, Brilliant walks you toward the insight through a sequence of guided puzzles. The production quality is high, and the approach works well for learners who prefer discovering ideas before formally naming them. Coverage extends beyond math into science and CS. The limitation is that it's not a strict sequential curriculum, and there's no spaced repetition for long-term retention. Best for: learners who enjoy exploratory, puzzle-driven study across multiple subjects.
Duolingo Math applies the Duolingo model to basic numeracy — short sessions, streaks, hearts, low friction. It's well-executed for what it is, but the ceiling is low: the curriculum doesn't extend far beyond elementary and middle-school level. If you want to maintain basic arithmetic fluency or build a study habit with minimal effort, it works. If you want to actually advance mathematically, it runs out of content quickly. Best for: keeping basic math familiar, building a daily habit, complete beginners who want very low friction.
Photomath and Mathway are answer tools, not learning tools. You input a problem, you get a solution with steps. This is genuinely useful for checking work or understanding a specific problem you're stuck on. The risk is substituting answer-getting for understanding — it's easy to follow a step-by-step solution and feel like you learned something without actually being able to reproduce that reasoning independently. Best for: checking work, getting unstuck on a specific problem, supplementary reference.
MathJourney is built for adults who want to learn mathematics properly — not supplement a course, not solve a specific problem, but actually build a solid and lasting mathematical foundation from the ground up. The curriculum is a deliberate progression from Foundations through Fractions, Pre-Algebra, Algebra, and all the way to Topology. Lessons are written for depth, not coverage. And the spaced repetition system ensures that everything you learn stays learned — not just for the week of a test, but permanently. Best for: adults learning math seriously, people with gaps from school, self-studiers who want a complete structured path with long-term retention.
The right platform depends on your goal. If you need free content quickly, Khan Academy. If you enjoy puzzle-based exploration across subjects, Brilliant. If you want a low-friction daily habit for basic math, Duolingo Math. If you want to actually learn mathematics — systematically, deeply, and permanently — MathJourney is built for that specific goal. The platforms above are tools. MathJourney is a curriculum.