exams shape college admissions. CLEP exams save thousands in tuition. But the best prep tools cost hundreds of dollars — or require hiring a tutor. PrepLion exists to change that: world-class AI-powered CLEP & DSST, CLEP & DSST prep, free for every student.
For college students, CLEP and DSST exams offer a way to skip intro courses and save thousands — but there's almost no quality prep out there beyond outdated practice books.
We built PrepLion to solve that problem. A platform that does what a great tutor does: explain why, not just what — then test whether it clicked.
Sage, our AI tutor, is the result of that idea: a study partner that's available 24/7, never gets impatient, and adapts to exactly where you're struggling — whether you're aiming for a passing score on CLEP College Algebra or DSST Business Ethics.
Our Mission
“Make world-class CLEP & DSST, CLEP & DSST prep accessible to every student — not just those who can afford a tutor.”
Active recall. Research consistently shows that actively retrieving information — not passively rereading notes — is the most effective way to move knowledge into long-term memory. Every PrepLion practice question and every Sage comprehension check is an act of retrieval.
Spaced repetition. When you answer a question wrong, PrepLion schedules it to reappear at increasing intervals. This technique has been shown in cognitive science studies to dramatically improve retention over weeks and months compared to massed practice.
Mastery-based progression. Rather than assigning the same material to every student, Sage tracks your mastery by unit and generates questions targeting your weakest areas first. This approach — rooted in Bloom's mastery learning framework — ensures that practice time goes where it has the most impact.
Comprehension verification. After Sage explains a concept, it offers an optional 3-question check to verify you understood the explanation — not just read it. This closes the loop between passive learning and active demonstration of understanding.
Every CLEP practice question goes through a rigorous 9-step quality pipeline
Topic Distribution
Questions match College Board’s official exam topic weights
Bloom’s Taxonomy
50%+ questions test application and analysis, not just recall
Scenario-Based
80%+ of questions present real-world scenarios, matching CLEP’s format
Misconception-First Distractors
Wrong answers target actual student misconceptions
AI Generation
Gemini 2.5 Pro generates questions calibrated to intro-college level
Cross-Model Validation
A second AI model independently validates every question
8-Criterion Review
Factual accuracy, single correct answer, distractor quality, cognitive level, exam alignment, scenario check, distractor distinctness, explanation quality
Difficulty Calibration
Empirical tracking ensures questions match real CLEP pass rates
OpenStax Grounding
Factual accuracy verified against free, peer-reviewed college textbooks
34 College Board CLEP exam topic distributions aligned
120+ original calibration question stems validated against
PrepLion is not affiliated with or endorsed by the College Board. CLEP® is a registered trademark of the College Board.
Instant Feedback on Every Answer
Every MCQ and FRQ gets an immediate explanation of why the correct answer is right and why each wrong answer is a common misconception. No waiting, no answer keys.
Mastery Tracking Across All Units
Your dashboard shows per-unit mastery percentages, accuracy trends over time, and a visual heatmap — so you always know exactly where to focus your next study session.
Adaptive Study Plans
Each week, Sage generates a study plan that targets your weakest units first and adjusts recommendations as your scores improve. Set your exam date and the plan counts down with you.
Here's what the experience looks like — from your personalized study plan to practice questions with instant AI feedback.
Master Units 4 & 5 before Friday
Focus Areas
Unit 4: Revolutions
41% mastery — 12 MCQs recommended
Unit 5: Cold War
63% mastery — 8 MCQs recommended
Unit 2: Exploration
74% mastery — 5 MCQs to reinforce
Mon: Unit 4 MCQs
Tue: Unit 5 Review
Wed: Mixed Practice
Thu: Weak Topics
Prioritized weekly plan by unit
MCQ · Unit 5: Revolutions
Which of the following BEST explains why the French Revolution spread ideas of democracy across Europe?
Napoleon's military campaigns (1799–1815) carried Revolutionary ideals of liberty and nationalism into conquered territories, abolishing feudal privileges across Europe.
Instant Sage explanations
78%
Accuracy
342
Questions
12d
Streak
2,450
XP
Mastery by Unit
Accuracy Over Time
Per-unit mastery tracking
Outcome-Obsessed
We measure success in score improvements, not time-on-site.
Accessible First
Core features are free. Always. Premium is for students who want more — not a paywall for the basics.
AI as a Teacher
Sage doesn’t just answer questions. It explains, checks your understanding, and adapts to your weak points.
CLEP (College Credit)
DSST (College Credit)
50
Courses covered
34
CLEP exams (college credit)
24/7
AI tutor availability
Free
To start, forever
$9.99
Premium per module/mo ($79.99/yr)
The first standalone release of PrepLion — a dedicated CLEP & DSST exam prep platform for adult learners, rebuilt with a Khan Academy-inspired design.
CLEP & DSST Only
56 exams across CLEP and DSST — no AP, SAT, or ACT. Purpose-built for adult learners earning college credit.
Khan Academy-Inspired UI
Warm, approachable design with generous spacing, larger touch targets, readable text, and a mobile-first layout across every page.
Full Platform Rebrand
New identity, color palette, service worker, and branding — PrepLion is now a fully independent platform with its own GitHub repo and deployment.
Production-Ready Stack
Next.js 14, Prisma + Neon, Cloudflare Pages deployment, AI tutoring via Groq, and Stripe billing — all migrated and verified.
Per-module subscriptions, SEO overhaul, content optimization, and strict course filtering.
Per-Module Stripe Subscriptions
Independent $9.99/mo subscriptions for CLEP & DSST, and CLEP. Subscribe to exactly the modules you need. Cancel or reactivate each independently.
Module-Locked Sidebar
Sign up from /clep-prep → see only CLEP courses. DSST → only DSST. No more seeing all 56 courses — focused experience from day one.
SEO & Content Overhaul
JSON-LD structured data, OG images, XML sitemap, 4 dedicated prep landing pages with study flows, outcome messaging, and parent trust sections.
Outcome-Driven Copy
Every page now leads with results: score improvements, prep timelines, cost savings. Comparison tables vs tutors and ChatGPT on pricing page.
Track-based segmentation — high school and college students now get fully separate, focused experiences from the first click.
CLEP vs CLEP/DSST Tracks
Students now choose their path — 'Start CLEP/DSST Prep' or 'Start CLEP Prep' — from the landing page. The chosen track is remembered across sessions via localStorage.
Track-Filtered Onboarding
Onboarding Step 1 now shows only CLEP courses (emerald accent) or DSST courses based on the student's chosen track.
Track-Filtered Sidebar
The sidebar course switcher shows only CLEP groups (for CLEP-track users) or only CLEP/DSST groups. A 'Switch to...' link is always visible as an escape hatch.
Smart Course Defaults
First-time CLEP-track users default to CLEP College Algebra. First-time DSST-track users default to DSST Business Ethics. Existing users see zero change — their stored course is preserved.
Track-Aware Register Page
The registration page subtitle dynamically reflects the student's chosen track — 'Start earning college credit' for CLEP, 'Start your exam prep journey' for CLEP/DSST.
CLEP college-credit prep arrives — 34 CLEP exams with full AI tutoring, practice, and mastery tracking. Save up to $2,400 in tuition per exam.
34 CLEP Exams — Full Catalog
All 34 official CLEP exams across 5 domains: Composition & Literature, History & Social Sciences, Science & Mathematics, Business, and World Languages — each with 5 units and full AI support.
Sage Tutors CLEP Content
Our AI handles CLEP and DSST subject matter — with resources from OpenStax, Khan Academy, and Wikipedia.
Separate Sidebar Section
CLEP courses appear as a dedicated 'CLEP Prep' tab in the course switcher, fully isolated from CLEP/DSST content.
Legal & Copyright-Safe
All CLEP practice questions are original AI-generated content. Resources are from openly licensed sources (OpenStax CC BY, Khan Academy, Wikipedia). CLEP® is a trademark of College Board, which does not endorse this platform.
Audience-Split Landing Page
The home page now speaks directly to both CLEP and DSST students — with dedicated audience cards, dual CTAs, and above-the-fold ROI messaging for each track.
Previous releases (Beta 1.9 – 1.14) introduced daily streaks, spaced repetition, voice input, automated question bank seeding, admin dashboard redesign, annual billing, and a 7-day money-back guarantee.
Have a question, found a bug, or want to suggest a course? We read everything — reply within 24 hours.
contact@preplion.aiFor pricing details, see the Pricing page.
CLEP® is a trademark registered by the College Board, which is not affiliated with, and does not endorse, this product or site. DSST® is a trademark owned by Prometric, which is not affiliated with, and does not endorse, this product or site.
PrepLion is an independent educational technology platform. All practice questions and study materials are original works created by PrepLion and AI models — not reproduced from any official exam publisher. CLEP curriculum references use publicly available subject descriptions and freely licensed resources (OpenStax CC BY 4.0, Khan Academy, Wikipedia CC BY-SA).