CertScroll, at study.wanessalabs.com, is a free practice site for ten AI and machine learning certifications. Much of what these exams test overlaps: embeddings, attention, fine-tuning, retrieval, evaluation, safety. CertScroll is built around that overlap. One bank of 45 shared concepts links to every certification, so practice for one exam counts toward the others.
There is no account and nothing to sign up for.
The certifications
| Provider | Certification or course |
|---|---|
| AWS | Certified Machine Learning Engineer, Associate |
| Anthropic | Claude Certified Architect, Foundations |
| Anthropic | Claude Code in Action |
| Anthropic | AI Fluency: Framework and Foundations |
| Google Cloud | Generative AI Leader |
| NVIDIA | Generative AI and LLMs (NCA-GENL) |
| Databricks | Generative AI Fundamentals |
| Hugging Face | AI Agents Course |
| IBM | AI Engineering Professional Certificate |
| Oracle | OCI Generative AI Professional |
Certification names appear as plain text only. CertScroll is independent and not affiliated with any provider.
The question feed
The home page is a feed of multiple-choice questions, about 2,000 in all. Pick a certification or a cluster of related certifications to narrow it. Answer a question and you see why each wrong option is wrong. If you miss one, Reinforce concept gives you more questions on the same idea.
Questions come in four levels:
| Level | What it tests |
|---|---|
| Recall | Definitions, parameters, and the basic mechanics |
| Discrimination | Telling similar approaches apart, such as LoRA and QLoRA |
| Application | Sizing and tuning a real system, such as GPU memory for a given model |
| Diagnosis | Finding the cause when something fails in production |
Questions you know well come back less often. When everything is marked known and nothing is due, the feed says so.
Keyboard shortcuts: A to D (or 1 to 4) pick an answer, J or the down arrow moves to the next question, K or the up arrow goes back, Space skips ahead once you have answered, ? shows the full list, and Esc closes it.
Audio mode reads questions aloud, at four speeds, with optional auto-advance, for studying away from the screen.
Mock exams
The Exams page builds a timed mock exam for any certification: 15 questions as a sprint, 25 as a standard check, or 50 as a full simulation. CertScroll samples questions in proportion to the exam’s published domain weights and spread across the four levels. You can flag questions, pause, and resume.
At the end you get a breakdown by domain, the concepts that need work, a review of every question you missed, and a button to start a drill on just those concepts. Scores of 70% or more are marked as a pass. This is a practice benchmark. Each real exam sets its own pass mark.
Other pages
- Concept and certification pages explain each concept, which exams test it, and link out to free official training, exam guides and public videos.
- Bank is an interactive map of the whole question bank and how the concepts connect.
- Lab has hands-on comparisons of prompting techniques, such as chain-of-thought and sampling settings, a step-by-step view of an agent loop, and a red-team challenge where you try to break a prompt’s defenses.
- Progress shows your first-try accuracy, your streak, the concepts that are shaky, and the wrong answers you tend to pick.
Where the questions come from
Every question is original, written from the provider’s own published exam guide. None is copied or reconstructed from a prep site, a braindump or a real exam. Every question names the section of the exam guide it was written from, and the build rejects any question whose source cannot be matched to that guide.
Most questions were generated from the concept bank and checked against the guide automatically. A small number have been read by a person. Each question says which it is, under Checked: either who read it and when, or “Not individually read.”
Your data
Your answers, review schedule, exam scores and streak are stored only in your browser. Nothing is uploaded, and the site cannot see it.
Because progress lives on one device, a different browser or a cleared cache starts over. To move progress between devices, use Export Progress on the Progress page to save a backup file, then Import Backup on the other device. Reset All Data clears everything.
There are no ads, no tracking cookies and no third-party trackers. Cloudflare’s cookieless analytics count page visits without identifying you. The site can be installed as an app and keeps working offline for the pages you have opened.
For developers and AI agents
The question bank is also published as read-only JSON, with no key needed:
/api/v1/certs/index.jsonand/api/v1/concepts/index.jsonfor the certifications and concepts/api/v1/questions/index.jsonfor the first 100 questions, and/api/v1/questions/<id>.jsonfor any single question/api/v1/openapi.jsonfor the full specification
For connecting an AI agent or coding tool over the Model Context Protocol, see the MCP page on the site.