TL;DR: CloudPrep is a free practice simulator for the AWS Certified Cloud Practitioner (CLF-C02) exam. It has 2,000 original questions, an explanation for every option, real-format 65-question / 90-minute mock exams, and an optional on-device AI proctor. No ads, no paywall.
👉 Try it: aws-cloud-prepare.vercel.app
🤔 Why I built it
CloudPrep started as my own preparation tool for the CLF-C02 exam. I wanted practice that felt like the real exam: the same length, the same timing, the same pressure. I also wanted every answer explained and backed by an AWS source.
So I built it, and then made it a free, public product so anyone preparing for the exam can use it too.
📊 CloudPrep at a glance
| 📚 2,000 | ⏱️ 65 / 90 | 🧩 4 | 💸 Free |
|---|---|---|---|
| original questions, each option explained | questions and minutes, like the real exam | exam domains, weighted like the official guide | no ads, no paywall |
The questions are split across the four CLF-C02 domains:
| Domain | Exam weight | Questions in CloudPrep |
|---|---|---|
| 1. Cloud Concepts | 24% | 400 |
| 2. Security and Compliance | 30% | 600 |
| 3. Cloud Technology and Services | 34% | 753 |
| 4. Billing, Pricing, and Support | 12% | 247 |
✨ What you can do with it
1. 📖 Learning mode: practise at your own pace
- Untimed practice by domain or topic
- Instant feedback with an explanation for every option, not just the correct one
- Links to the AWS documentation each question is based on
- Bookmarks for questions you want to revisit
- Review due: missed questions come back on a schedule so you see them again before you forget them
Review schedule: 1 day → 3 days → 7 days → 21 days → 60 days
💡 Learning mode works without an account. Just open the site and start practising.
2. ⏱️ Timed mock exams: the real thing, before the real thing
- 65 questions in 90 minutes, following the CLF-C02 domain weightings
- Flag questions, jump around with a question grid, and do a final review
- Auto-submit when the timer runs out
- An exam-paper style answer sheet
- The timer counts down to a fixed end time, so it survives reloads
3. 📈 Results that tell you what to fix
- Practice score with a per-domain breakdown
- Answer review with explanations
- Exam history and progress guidance across attempts
- The dashboard flags your weakest domain and shows the time used in recent exams
4. 🤖 AI-proctored exams (opt-in)
Want to train under real exam conditions? Turn on the AI proctor.
- A check-in, like an online proctored exam
- MediaPipe face and object models plus microphone loudness, all running on your device
- It watches your face, head, eyes and mouth, looks for phones, other people, books and screens, and blocks shortcuts
- Two warnings, then the exam ends. A phone or another person ends it at once.
🔒 Nothing is recorded or uploaded. It all runs in your browser.
There's also a lighter strict mode that asks for fullscreen and logs tab and focus changes, without judging them.
5. ☁️ Sync across devices
- Sign in with Google to save your progress, bookmarks, exam history, the exam in progress and settings to your account
- Everything follows you to every device
- A copy is kept in the browser, so it stays fast and works offline. Changes sync when you're back online.
6. 🎨 Designed for long study sessions
- Light theme and a true-black dark theme
- Serif titles, rounded cards and an exam-paper answer sheet
- Add to Home Screen support with its own icons
- Automated axe accessibility checks (WCAG 2.2 AA rules) pass on every page, in both themes
👥 Guest vs signed in
| Feature | Guest | Signed in (Google) |
|---|---|---|
| Learning mode | ✅ | ✅ |
| Bookmarks and settings | ✅ (this browser only) | ✅ (synced) |
| Timed mock exams | ❌ | ✅ |
| Dashboard, history and progress | ❌ | ✅ |
| Sync across devices | ❌ | ✅ |
🛠️ Tech stack
For the developers reading this, here's what's under the hood:
| Layer | Tech |
|---|---|
| Frontend | React 19, TypeScript (strict), Vite 8, Tailwind CSS 4, React Router |
| Backend | Supabase only: Postgres with Row Level Security + Supabase Auth (Google). No separate API server. |
| Data | Questions loaded at runtime and cached in IndexedDB; user data in a versioned localStorage layer, synced to Supabase when signed in |
| AI proctor | MediaPipe face and object models, running on-device |
| Testing | Vitest + Testing Library (database schema and security rules run in PGlite), Playwright + axe for E2E and accessibility |
| Hosting | Vercel (static SPA) |
🧾 Honest notes
I'd rather you trust it for the right reasons, so:
- ⚠️ CloudPrep is not affiliated with or endorsed by AWS. A practice score doesn't predict or guarantee an official result.
- 📊 It shows the percentage you got right. It does not estimate AWS's scaled 100–1,000 score.
- ✍️ The questions are original, written with AI assistance from public AWS documentation and the official exam guide, then checked against the pages they cite. They are not copied from the real exam or from dumps.
- ✅ 1,995 of the 2,000 questions are checked against their AWS sources; 5 are still marked unverified.
🚀 Try it and tell me what you think
If you're preparing for the AWS Cloud Practitioner exam, give it a go:
👉 aws-cloud-prepare.vercel.app
I'd love your feedback:
- 💬 Found a question that's wrong or unclear? Tell me in the comments.
- 🐛 Something broken on your browser or device? Let me know.
- ⭐ If it helps you, share it with someone who's preparing for the exam.
Good luck with your exam! ☁️
Preparing for frontend interviews too? Check out Frontend Interview Prep, with React and JavaScript interview questions and answers.
Made by Shubham Chaudhary · Portfolio
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