“I finished the Khan Academy unit, but my professor’s slides still make no sense. What now?” It’s a fair question, and the answer depends on what is missing. If you need a free lesson on a standard topic, you may not need to leave Khan Academy at all. If you need extra practice, a different teaching style, or help with your own course files, a different tool fits better.
Below we compare CK-12 Flexi, IXL, Brilliant, ChatGPT Study Mode and BoredProf, then give a decision by need. Disclosure: BoredProf publishes this article. We have not run hands-on tests of the other tools, so each row rests on the tool’s own pages or the sources linked. We also don’t claim any tool improves grades.
TL;DR
- Stay with free Khan Academy if you want standard lessons and practice in a structured library. Khan Academy describes itself as free for teachers, students and families.
- Khanmigo is Khan Academy’s paid AI add-on, so it belongs with Khan Academy rather than being an unrelated rival.
- Pick IXL for skill-by-skill drills, Brilliant for short interactive problems, CK-12 Flexi for a free school-level AI helper, and ChatGPT Study Mode for open-ended questions.
- Pick BoredProf when the material is your own lecture slides, PDFs or a homework photo and you want it explained out loud and drawn step by step.
Quick comparison table
Prices were last read from BoredProf’s site on 3 November 2026. For every other tool, the figure that matters (package, child count, region, billing) is set on the official pricing page linked in the table, so confirm it there on the day you buy.
| Tool | Learner and subjects | Format | Free limits | Price and billing | Main drawback |
|---|---|---|---|---|---|
| Khan Academy | School through early college, many subjects | Lessons and practice | Core library free | Free; Khanmigo is a separate paid add-on | Content follows Khan’s course map, not your syllabus |
| CK-12 Flexi | K-12 STEM | AI helper plus lessons | Free | Free | School-level focus; not built around your own files |
| IXL | Pre-K to grade 12; 20,000+ skills across math, language arts, science, social studies and Spanish | Practice and diagnostics | Limited without membership | Membership; price depends on package and number of children | Drill-heavy; light on instruction |
| Brilliant | Teens and adults; math, CS, science, data | Short interactive problems | Trial or limited access | Subscription; price depends on region and billing choice | Not tied to a specific course |
| ChatGPT | Anyone with an account; any subject | Conversational AI | Free tier with optional paid plans | Free plus optional paid plans | Answers are only as good as your question; you must check them |
| BoredProf | Ages 13+; math, physics, chemistry, biology | Spoken whiteboard tutoring on your own files | Free plan: one lecture from one course, with stated caps | Free; Pro C$29.99/month; Max C$59.99/month | Course-specific; not a replacement for a full curriculum or a human tutor |
When free Khan Academy is the best choice
Suppose you are stuck on solving linear equations. Khan Academy gives you a lesson, practice and hints at no cost. That covers most standard topics.
Why stay: if your question is “teach me this topic from scratch,” a free, organized library answers it directly. Leaving only makes sense when the gap is different: your professor’s notation, a practice-volume problem, or a file only you have.
A quick test: can you name the topic as a textbook chapter title? If yes, start with Khan Academy. If your question starts with “on slide 14 my professor wrote…”, read on.
Khanmigo: the paid AI add-on
Khanmigo is Khan Academy’s AI tutor, an add-on to the same ecosystem. If you like Khan’s style and want conversation on top, it is the closest step up. Check Khan Academy’s own site for the current price and who is eligible.
Which learning format do you need?
Before comparing brands, decide what kind of help you are missing. Tools differ less by name than by format.
| Need | Format | Examples |
|---|---|---|
| Learn a topic from zero | Lesson library | Khan Academy, OpenStax textbooks |
| Build speed and accuracy | Practice platform | IXL, reef.science |
| Build intuition | Interactive problems | Brilliant |
| Ask questions about your own material | AI tutoring | BoredProf, ChatGPT Study Mode, Khanmigo |
If you are a teacher or tutor looking for classroom-ready software with AI features, you can also browse AI tools for classrooms.
CK-12 and Flexi: free, school-oriented help
CK-12’s Flexi is an AI helper from a free educational resource. It sits closest to Khan Academy in spirit: free, aimed at K-12 STEM, built around standard school topics.
Worked example. Ask Flexi, “What is the difference between speed and velocity?” You get a short, curriculum-style explanation. The step that matters: velocity includes direction, so a car circling a track at constant speed still changes velocity. That answer is general, which is the point and the limit. Flexi explains the textbook idea, not what your instructor emphasized.
Best for: high school students who want free STEM explanations. Skip if: your questions depend on a specific course file.
Quick check: a runner completes one lap of a track and ends at the start. Is the average velocity zero? (Yes: displacement is zero, so average velocity is zero even though the speed is not.)

IXL: practice at scale
IXL is a practice platform. It lists more than 20,000 skills, a Real-Time Diagnostic, personalized skill recommendations and analytics, which suits families who want to see which skills are solid. Its family pricing page sets the price by package and number of children, so the cost for a family with two kids differs from a single learner’s.
TeachThought notes that IXL works best for identifying and practicing specific skills, alongside richer instruction.
Worked example. You miss three fraction-addition questions. IXL’s value is that it keeps serving similar problems until the pattern holds. Why that helps: fraction errors usually come from one repeated slip, like adding denominators, and repetition exposes it.
Best for: parents and students who need volume and a skills map. Skip if: you need someone to explain why, out loud, from your own notes.
Brilliant: learn by solving short problems
Brilliant teaches through short interactive problems in math, computer science, science and data analysis, with 40+ courses from grade 5 through college, and an AI tutor named Koji. TeachThought says it suits visual problem solving and conceptual understanding. Pricing depends on region and billing, so use its subscription page for today’s number.
Worked example. A Brilliant puzzle might ask you to predict what happens to a shape’s area when you double one side before showing any formula. You commit to a guess, see it fail, then adjust. The step follows from the design: guessing first makes the formula answer a question you already have.
Best for: curious learners who like puzzles. Skip if: you have an exam on Thursday covering a specific professor’s material; Brilliant is not organized around your course.
ChatGPT Study Mode: flexible, but you drive
ChatGPT offers a free tier and optional paid plans on its pricing page. In a study-style conversation you can ask anything, in any subject, and get follow-ups.
Worked example. Paste a problem and ask, “Quiz me step by step instead of giving the answer.” The tool asks for your first step, then the next. Why this works: you produce each step, so a wrong turn shows up early.
The tradeoff: it is a general chatbot, so you steer the session and you must check each answer against your textbook or notes. AI-assisted learning goes deeper on using any AI tool well.
Best for: students who know exactly what to ask. Skip if: you want a board, drawn steps and a spoken lesson built from your slides.
BoredProf: your own slides, explained and drawn
BoredProf is an AI whiteboard tutor for students studying their own course materials. You upload lecture slides, PDFs, Word or PowerPoint files, or a homework photo. It explains ideas out loud and draws steps and figures on a whiteboard, with voice chat, captions, follow-up questions, saved lessons and feedback on handwritten working. The public site shows math, physics, chemistry and biology.
Worked example. Your slide shows the derivative of x² as 2x with no explanation. In a lesson built from that slide, the board would write the limit definition, expand (x + h)², cancel x², and let h shrink to zero. Why each step follows: expanding creates the terms to cancel, canceling leaves a factor of h, and dividing by h makes the limit computable. You can interrupt at any point to ask, “Why does the h² vanish?” See more on the worked examples page, and our calculus guide if limits are the sticking point.
Quick check: using the same steps, what is the derivative of x³? (3x², since (x + h)³ expands to x³ + 3x²h + 3xh² + h³, and the leftover terms vanish as h goes to zero.)
Best for: college and university students, and high school students aged 13+, who learn from their own course files. Skip if: you want a complete school curriculum or a human tutor. We designed BoredProf for course-specific understanding, not to replace either. We don’t promise grades, perfect accuracy or unlimited use.

Plans and prices
Prices below were read from our site on 3 November 2026, in Canadian dollars. USD options differ, so confirm both currency and eligibility on the terms page before you pay.
| Plan | Price | Notes |
|---|---|---|
| Free | C$0 | One lecture from one course, with stated usage caps; no card |
| Pro | C$29.99 per month | Also listed on the terms page as C$99 per 4 months (paid up front) |
| Max | C$59.99 per month | Expanded access |
Monthly plans carry no annual upfront charge; the 4-month option is billed as one payment. Legacy founding prices apply only to qualifying pre-launch waitlist users. The public demo uses prewritten sample answers drawn on the real board, so it shows the format rather than a live session on your files.
Try it on your own material
If your next problem set or lecture deck is what’s stuck, the free plan lets you see how a spoken, drawn lesson handles one lecture from one course. No card is needed. Start free, or compare Pro and Max on the BoredProf pricing page.
If you are choosing between tutoring formats, our guides to an online physics tutor, chemistry tutor and biology tutor lay out what to look for.
Other options worth a mention
- OpenStax: free, peer-reviewed, openly licensed textbooks for high school and college, readable online with no login. Best for students who want the textbook itself.
- reef.science: 20 university-level STEM courses and 1,148+ practice problems, free, with step-by-step solutions. Best for college STEM practice.
- ALEKS: math from elementary through precalculus, plus chemistry, statistics and accounting, beginning with an assessment. Individual plans are $19.95 for one month up to $179.95 for 12 months, one course at a time.
- Coursera and edX: university-style courses. Coursera Plus costs $239/year, while edX is pay-per-course for certificates. Best for full courses, not homework help.
Questions to ask before you choose
- Is the material mine or generic? Generic topics suit Khan Academy, CK-12 or Brilliant. Your own slides suit a tool that reads your files.
- Do I need explanation or repetition? Explanation: lessons and tutoring. Repetition: IXL or reef.science.
- What is the age rule? BoredProf’s terms require age 13+. Check each tool’s terms for age and parent access before a younger student signs up.
- What does the free tier cover? BoredProf’s covers one lecture from one course. Read each tool’s free limits before relying on it.
The point of a quick check after each lesson is to make sure you can do the next problem alone. Try the mistake-review method after any tool you use.
Decision by need
| If you need… | Pick |
|---|---|
| Free, structured lessons on standard topics | Khan Academy |
| An AI conversation inside Khan’s world | Khanmigo |
| Free STEM help at school level | CK-12 Flexi |
| Skill drills and a progress map | IXL |
| Puzzle-style conceptual learning | Brilliant |
| Open-ended questions you steer yourself | ChatGPT Study Mode |
| Your own slides explained aloud and drawn | BoredProf |
Many students combine two: Khan Academy for the basics, plus one tool for their own course material.
FAQ
Is there anything better than Khan Academy?
It depends on the gap. For free standard lessons, Khan Academy is hard to beat. For your own lecture files, a tool built around uploads, like BoredProf, fits more directly.
Is IXL or Khan Academy better?
They do different jobs. Khan Academy teaches topics for free, while IXL drills skills with diagnostics under a membership whose price depends on package and number of children.
What is the best website to learn math for free?
Khan Academy, CK-12 and OpenStax are free starting points for school and college math. BoredProf’s free plan also covers one lecture from one course if you want it explained from your own slides.
Is Khanmigo an alternative to Khan Academy?
No, it is Khan Academy’s paid AI add-on. Treat it as an upgrade within Khan’s ecosystem.