Last updated: August 12, 2026
Qinno is a free web app for SAT and AP exam practice. It turns practice into timed head-to-head matches: you answer the same questions as an opponent, and answering correctly and quickly scores more than answering correctly and slowly. Every question you miss is collected in a mistake book with an AI explanation.
Qinno covers five subjects: SAT Math, AP Calculus AB, AP Calculus BC, AP United States History, and AP Psychology.
The banks hold 836 questions in total: 564 written for timed battles and 272 written for untimed practice. Practice questions are deliberately harder on average, because they are not played against a clock.
A match is five questions long. Each question has its own time limit, set by subject and difficulty — 45, 75, or 120 seconds for SAT Math, and 60, 90, or 150 seconds for AP Calculus, for example.
A correct answer scores 100 points plus up to 200 more, in proportion to the time remaining when you answered. A wrong answer or a timeout scores nothing. The maximum for one question is 300.
The last question of every match is always drawn from the hardest tier, so a match is decided at the end rather than in the middle.
There are three ways to play. In a real-time battle you create a room, send the link, and both players answer simultaneously while the scores update live.
In an asynchronous challenge you send a link that a friend can open whenever they want. Your run is recorded, and they race your recording question by question.
Against Qinno Bot you play a full match alone, at any time. The bot sets its accuracy and speed from your recent scores, so matches stay close as you improve. This is stated openly in the app rather than hidden, because a difficulty adjustment that is noticed but not disclosed reads as cheating.
Questions are built against the published design of the real exams rather than assembled as a generic quiz bank. Domain weightings follow the official breakdowns: SAT Math is 35% Algebra, 35% Advanced Math, 15% Problem-Solving and Data Analysis, and 15% Geometry and Trigonometry.
Every wrong option corresponds to a specific mistake a student actually makes — dropping the inner derivative of a chain rule, reading a rate as a total, using left endpoints where the question asks for right. An option that no identifiable error produces is treated as a defect and replaced.
AP United States History questions hang on labelled historical sources and are organised around the six official historical thinking skills, which is how the real multiple-choice section is built.
SAT Math practice includes student-produced response questions, where the answer is typed rather than chosen from four options. About a quarter of the real SAT Math section works this way.
Every question you answer incorrectly, in a battle or in practice, is added to your mistake book automatically. There is nothing to tag or save.
Each entry shows the question, the answer you gave, the correct answer, and an AI explanation that works through the method and then accounts for each wrong option in turn. Explanations are limited to five per day.
Mistake practice serves only your own missed questions. Answer one correctly and it leaves the rotation; miss it again and it stays.
Qinno is free. There are no paid tiers, no advertising, and no in-app purchases.
You can play a full demo battle without creating an account. An account is needed to keep a mistake book, track statistics, and create challenges, and it requires only an email address.
Qinno is a web app and runs in any modern browser on any operating system, including phones and tablets.
It can also be installed from the Microsoft Store on Windows, or added to a home screen on iOS and Android. All of these open the same product and share the same account and progress.
Qinno is an independent project, not affiliated with or endorsed by the College Board, which owns the SAT and AP trademarks. References to those exams describe what Qinno prepares students for.
Corrections to a question, bug reports and suggestions are welcome. There is a feedback form on the profile page inside the app, a report button on every mistake-book entry, and email at HTQ1235@outlook.com.