Your AI study buddies, Chad & stacy

Flashcards that come back right before you'd forget. An AI that explains like a friend. A planner that reads your syllabus. Free to start.

Start studying free →I have the app — sign in
Free to start ◆11 study tools in one app ◆Real spaced repetition (FSRS) ◆Same account on web + iPhone
AI chat

An AI that explains it like a friend

Ask a question at 1am and get a real answer — then turn it into cards, a quiz, or a plan in one tap.

Stuck at 1am? Ask.

More about AI chat →
AI chat
What are we studying? Drop a topic and I'll make it stick.
Explain the Krebs cycle like I'm tired…
Alright, tired-brain version: The Krebs cycle is how your cells burn fuel for energy. Acetyl-CoA joins oxaloacetate and spins through eight steps. Each turn spits out carbon dioxide, a little ATP, and the electron carriers NADH and FADH2 that feed the next stage. Two turns per glucose. That is the whole loop.
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Flashcards

Cards that come back right before you forget

Grade honestly and FSRS schedules each card for the moment you’re about to lose it. Less re-reading, more remembering.

Re-reading feels good. Retrieval works.

More about flashcards →
Flashcards
Good → comes back in 4 daysGrade honestly. FSRS does the scheduling.
Live quiz

Studying together, minus the scheduling pain

Shared sets, group chat, and live quiz games with a leaderboard — the reps become something you show up for.

Leaderboards make the reps something you show up for.

More about study groups →
Live quiz
Which organelle makes ATP?
+870
1. you870
2. maya850
3. dev_notes720

Two minutes to set up. Your first set writes itself.

Start studying free →
Planner

A semester that plans itself

Drop in your syllabus and get review blocks spaced backward from every exam — the way a tutor would lay it out.

Drop the syllabus. Get the plan.

More about the planner →
Planner
Bio 101 syllabus: Midterm — Oct 14
Mon
Tue
Wed
Thu
Fri
Midterm
Thu
Review
Bio 101
Review
Bio 101
Review
Bio 101
Spaced backwards from the exam — like a tutor would.
Practice exams

Take the test before the test

AI practice exams built from your own notes — multiple choice grades itself, and every short answer comes with a model answer to check yours against.

The first attempt shouldn’t be the real one.

More about practice exams →
Practice exam
In glycolysis, what does hexokinase do?
Hexokinase adds a phosphate to glucose, releasing energy to start the pathway.
Model answer: hexokinase adds a phosphate to glucose — that step uses energy, it doesn’t release it. How’d yours line up?
Focus

Lock in when it counts

Start a focus session, keep your phone down, and watch the streak climb. Twenty-five minutes at a time.

25 minutes. No phone. Flame goes up.

More about focus →
Focus
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25 minutes. Streak +1. Take the break — you earned it.
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Lock-in zones

Turn your library into a focus switch

Draw a zone around where you study. Walk in and focus starts on its own — distracting apps shielded until you leave. (On iPhone.)

Arrive. Lock in. No decision required.

More about focus →
Lock-in zones
Library
Locked in
You walked into the library. Focus on, distractions off — automatically.

Pick Chad or stacy and start with one set tonight.

Start studying free →

Sets students already made

Real sets from the Discover catalog — preview any of them free.

Study set
Do Latter-day Saints believe in evolution? Ep. 139
16 cards · 0 saves · by A student
Study set
US History Exam Practice Quiz
11 cards · 0 saves · by Lena
Study set
I Beat Hardcore Minecraft at 1000x Speed on Half A Heart
24 cards · 2 saves · by Lena

Why it works

Active recall
Testing yourself beats re-reading. Every mode here makes you retrieve.
Spaced repetition
FSRS brings cards back right before you'd forget them.
Study together
Groups, leaderboards, and live quizzes make the reps something you show up for.

Who's behind it

Chad × Stacy is built by two college students who got tired of study tools that felt like homework. No ad model, no data selling — just the study science that works, wrapped in something you'll actually open.

Even better on your phone

Snap your notes into cards, lock in with app blocking, and keep your streak alive with reminders — iOS first.

Get Chad × Stacy

Questions, answered

What is Chad × Stacy?

An AI study app for college students. Pick your buddy — Chad (direct, hype) or stacy (warm, calm) — and study with flashcards, Learn mode, AI practice exams, study groups, and a planner that builds itself from your syllabus.

Is it free?

Yes — studying is free. AI features have a generous free tier, and Pro removes the caps.

Does the web version sync with the app?

Same account, same everything. Review a card here and your phone knows. Start a set in the app and finish it on your laptop.

Chad or stacy — what’s the difference?

Same brain, different voice. Chad gets you moving; stacy keeps you steady. The whole app recolors around your pick, and you can switch anytime.

Is my data private?

Yes — no ads, no selling data, no tracking cookies. The privacy policy is written in plain English.

Is using AI to study cheating?

Using AI to understand and practice isn’t; submitting its output as your own work is. Our honor code draws the line clearly.

Do I need the app?

No — the web app has everything. The iPhone app adds camera capture, notifications, and app-blocking focus.

What subjects does it work for?

All of them — from biology to law. Browse every subject to see how it fits yours.

Ready when you are.

Start studying free →