--- title: "An AI computer science tutor | DuckyHelper" url: "https://duckyhelper.com/subjects/computer-science/" description: "An AI computer science tutor: run your code against tests, step through it line by line to see the variables change, and get hints instead of the solution." updated: "2026-10-09" --- Mac app # An AI computer science tutor that lets you type DuckyHelper is an AI computer science tutor that teaches code by letting you write it. Run your function against tests and see what was expected and what you got. Step through it line by line and watch the variables, arrays and pointers change. Ask why it breaks and you get a hint, not the solution. In the Eddy tab, or, with Ducky, the next small chunk can appear as grey letters at your own caret. [Download for Mac](https://duckyhelper.com/download/)[Meet Eddy](https://duckyhelper.com/eddy/) “What is this for loop actually doing?” Watch it run. Step through it one line at a time and watch i, the total and the array change. Reading code is easier when you can see it run. Run and step through ## Run it. Step through it. Ask Eddy to run your code against a few tests and each one ticks in with what was expected and what you got. Ask what a loop does and a step-by-step player shows each line as it runs, with the variables, the arrays and their index pointers. In the Eddy tab it is a Code card on Eddy's desk; with Ducky it opens in the pill. [Guide: run and step through code](https://docs.duckyhelper.com/study/code/) A sandbox, not your computer Code runs in a sandbox with no internet, so trying something cannot break anything on your machine. Find where it breaks After a failing test, step to the line where the values go wrong and ask why. You get a hint about that line, not a rewritten program. ## Write it yourself, one chunk at a time In VS Code, on a practice site or in any text box, say walk me through writing this. Ducky says what the next small chunk does, then ghosts that code at your caret for you to type over. When you have typed it, the next step follows. The program is not pasted in for you: you type it. [Guide: tutorials in your apps](https://docs.duckyhelper.com/mac/tutorials/) Tutorials in your own tools Learning a new editor or terminal? Ask how to do something and Ducky shows each step on your real screen and waits until you have done it. Point at the error Hold fn and cmd and move the mouse over the error message: Ducky gets a picture with your path on it and explains that exact line. ## Five habits for learning to code What a session with a tutor looks like when the goal is that you can do it alone next time. 1. 1. Say your plan first Before any code, say in plain words what the program should do. Ducky asks about the case you skipped. 2. 2. Predict, then run Guess the output, then run it. The gap between your guess and the result is where the learning is. 3. 3. Step through the surprise When a test fails, step to the line where a value changes in a way you didn't expect. 4. 4. Take one hint at a time Ask for a nudge, not the fix. Then try again yourself. 5. 5. Explain it back When it works, explain why in your own words. Ducky asks about the line you glossed over. ## Keep going ### Coding interviews Practice out loud: your plan, the time cost, the edge case, with hints one at a time. ### Learning new software Step-by-step tutorials inside the apps you are learning, on a Mac. ### Run and step through code How the Code card works, in the DuckyHelper docs. ## Ask Eddy Say one of these out loud. What is this for loop doing? What is binary? Run my function against these tests Why is this recursion never stopping? [Download for Mac](https://duckyhelper.com/download/) ## How to use it [Guide: Your first lesson with Eddy](https://docs.duckyhelper.com/start/first-lesson/) ## Frequently asked questions ### Can an AI tutor teach me to code without writing it for me? Yes. DuckyHelper explains the next step, gives hints one at a time and checks your code by running it. In the Mac app, a code walkthrough ghosts one small chunk at your caret for you to type, so your hands write every line. ### Can it run my code? Yes. Ask Eddy to run your code against tests and each test shows what was expected and what you got. It runs in a sandbox with no internet, and a step-by-step player shows each line, the variables and the arrays. ### Does it work in my editor? On a Mac, yes: press fn in VS Code, on a practice site or in any text box, and Ducky sees your screen while the pill is open and can ghost code at your caret. In the Eddy tab, paste the code into Eddy. ### Does it work on a Chromebook? Not right now: DuckyHelper is a Mac app (macOS 14 or later, Apple silicon). There is no Chromebook or web version. On a Mac, the Code card runs and steps through code in the Eddy tab, and Ducky helps inside other apps. ## More subjects ### Math: worked steps, moving graphs, and hints before the answer An AI math tutor that explains one move at a time: worked steps, graphs you can move, hints before answers. In the Mac app, right over your homework. ### Biology: labelled pictures you can tap, read and quiz yourself on An AI biology tutor that answers with labelled pictures: ask how blood clots or how muscles move, tap any part to ask more, then quiz yourself. On a Mac. ### Chemistry: see the atoms, then work the equations step by step An AI chemistry tutor that shows what atoms are doing: labelled pictures of bonds, steps for every equation, quizzes and flashcards. In the DuckyHelper Mac app. ### Physics: simulations you can play with and every step worked through An AI physics tutor that shows the why: simulations you can play with, forces drawn out, worked steps with real numbers. In the DuckyHelper Mac app. ### History: labelled pictures, maps, timelines and sources you can check An AI history tutor that shows the past: labelled pictures, maps and timelines you can explore, and sources read with you and cited. In the DuckyHelper Mac app. ### Writing: feedback on your own draft, never a ghostwriter An AI writing tutor that reads your own draft with you, asks what you mean and points to what is unclear, and leaves the writing to you. On a Mac. ### Languages: speak out loud, get scored, and keep what you miss An AI language tutor you practice with out loud: hear a word in syllables, say it back, get each word scored, and keep what you miss as flashcards. ### Music: chords on a labelled keyboard, strings, scales and rhythm An AI music theory tutor that shows the sound: why a minor chord sounds sad on a labelled keyboard, how a string makes a note, rhythm in numbers. On a Mac. ### Art: perspective you can change, and paintings explained part by part An AI art tutor that shows how pictures work: perspective drawn on a picture you can change, paintings explained part by part, art history read with you. ## Keep reading ### Coding interviews: talk it through, run it against tests, step through the bug Practice coding interviews out loud: talk through your plan, get one hint at a time, run your code against tests and step through where it breaks. ### New software: a tutorial inside the real app, one checked step at a time Learn a new app inside the real app: DuckyHelper shows where to click on your own screen, waits while you do each step, and checks it. Mac app. ### Eddy: the voice tutor in the DuckyHelper Mac app's Eddy tab Eddy is the voice tutor in the DuckyHelper Mac app: talk out loud and it teaches on a blackboard, with labelled pictures, quizzes and your own homework file. ### Run your code against tests, then watch it step by step with every variable as it changes DuckyHelper runs your code against tests and plays it back step by step, every variable as it changes, so you see why it gives the wrong answer. ### Every subject: one question per subject, shown on screen DuckyHelper is an AI tutor for any subject: math, the sciences, history, writing, languages, code, music and art, each explained out loud and shown on screen. ## Write your next line yourself Get the Mac app and paste your code into Eddy, or press fn in your editor. [See what it does](https://duckyhelper.com/features/) The Mac app needs Apple silicon and macOS 14 Sonoma or later. There is no Chromebook, Windows or web version right now.