Learn CRO for free, one small lesson at a time

A practical conversion rate optimization course for beginners and busy marketers. Short, visual lessons, interactive case studies and free A/B testing tools show you why visitors leave and how to fix it.

  • 64 short lessons
  • No sign-up, ever
  • Reviewed by a CRO expert

The short answer

What is conversion rate optimization (CRO)?

Conversion rate optimization (CRO) is the practice of finding out why visitors don’t take the action you want, such as buying, signing up or booking a call, and then testing changes that remove those reasons. Your conversion rate is the share of visitors who complete that action: conversions divided by visitors.

Good CRO is not button colours or “best practice” lists. It is research first (analytics, recordings, surveys, user tests), then a clear hypothesis, then an A/B test or a careful rollout, then learning you can reuse. That is exactly the order this free CRO course teaches it in.

Read the full guide: what CRO is and isn’t

  • Research: find where and why people drop off
  • Hypothesis: one change, one reason, one metric
  • A/B testing: let real visitors decide
  • Analysis: read results honestly, including the flat ones
  • Rollout: ship what works and share the learning

What you’ll learn

From “why is nobody buying?” to “here’s what we’ll test next”

  • Spot where visitors leave

    Read a funnel and find the step that loses the most people.

  • Understand why they hesitate

    Use surveys, recordings and psychology to find the real reason.

  • Test ideas without guessing

    Run A/B tests you can trust, even if you hate statistics.

  • Explain results so people care

    Turn a test into a story your boss and clients actually read.

How CRO works

It’s a loop, not a magic trick

  1. Look

    Watch what real visitors do before changing anything.

  2. Guess smart

    Turn what you saw into an idea worth testing.

  3. Test

    Show the idea to half your visitors and compare.

  4. Keep what works

    Roll out the winners, learn from the rest, repeat.

In the course you’ll meet this loop by its full name in lesson 7. For now, four words are enough.

The free course

8 modules. 64 lessons. Zero to confident.

See the whole course

Case studies

Click through real problems, slide by slide

All case studies

Free tools

Answers to the three questions everyone asks

Psychology

Why people click, hesitate and buy

Browse principles

Who it’s for

CRO for beginners, and for the people who already do the work

  • Complete beginners

    Never heard of CRO? Lesson 1 starts at zero and builds one idea at a time.

  • Marketers and growth teams

    Turn traffic you already pay for into more leads, signups and sales.

  • Ecommerce and SaaS owners

    Find the leaks in product pages, checkout, trials and onboarding.

  • Designers, developers and analysts

    Learn the research, testing and statistics side so your work gets measured fairly.

Prefer a human?

Want someone to do it with you?

Learning here stays free. If you’d rather have senior CRO people on your funnel, your test backlog or your team, our partner team can help.

See how we can help

Questions people ask first

How do I learn CRO from scratch?

Start with how conversion rate is measured and why visitors drop off, then learn research methods, writing hypotheses, A/B testing and basic statistics, in that order. The free Mentorele course follows exactly that path in 64 short lessons, with case studies to practise on.

Is Mentorele really free?

Yes. Every lesson, case study, template and calculator is free to read. No account, no email gate. Paid help (consulting, mentoring, team training) is optional.

I have never done CRO. Can I start here?

That is exactly who lesson 1 is for. It starts at "what is CRO?" and builds up one small idea at a time. No maths needed until module 5, and we explain it when we get there.

Who writes the lessons?

Phil the CRO Guy, our guide, presents every lesson. Each one is checked by Filip Doneski, Lead CRO Strategist at Wavesy, with 10+ years in conversion optimization and experimentation.

Do I need paid tools to start with conversion rate optimization?

No. Free analytics, a free session recording tool and our free calculators are enough to learn and run your first research. A/B testing tools come later, and several have free plans. See our CRO tools guide for free options first.

How long does it take?

Most lessons take 5 to 10 minutes. Do one a day and you finish a module in about a week and a half.

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