$0
Price
100% free, donation-funded
Report
Should I Use Exercism?
Develop fluency in 83 programming languages — 100% free
Worth it
Worth itBuy if you already code and want free practice and mentorship across 83 languages.
Free, well-loved practice platform for 83 languages. Great for sharpening skills; not a from-zero teacher.
Confidence: Medium
2M+
Users
cited in 2024 founder blog
83
Languages
practice tracks from Python to niche ones
Nonprofit
Model
donations; 2024 restructuring over finances
Value for money
5
Everything free; donations optional
Ease of use
3
Beginners report confusion; assumes some experience
Feature depth
4
83 tracks, syllabi, mentorship, local CLI
Support quality
2
Volunteer mentors; shortages reported in some languages
Security posture
3
Minor CLI CVEs; no dedicated security page found
Pros
Cons
Gotchas
- medium2024 restructure over finances — free product's long-term runway is uncertain.²
- mediumMentorship speed varies by language; some tracks lack volunteer mentors.⁶
- mediumNewbies report it assumes prior experience — pair it with a beginner course.
- mediumNo org plans, SSO, or admin controls — don't buy it for company training.⁷
Best for
- Devs practicing a new language
- Self-taught coders wanting free mentor feedback
- Career switchers sharpening existing skills
- Fans of local-first, open-source tools
Not for
- Total beginners needing guided from-zero lessons
- Companies wanting team training features — no Teams product yet
- Interview-prep grinders (LeetCode fits better)
- Buyers needing SLAs, support guarantees, or SSO
Pricing
Free
$0
- All 83 language tracks
- Community mentorship
- Donation-supported
Security
No product breach found; minor CVEs affect the CLI tool, and no dedicated security page surfaced.
- CVE-2025-61723: quadratic complexity issueRed Hat Bugzilla tracks a quadratic-complexity CVE associated with exercism.⁸
- Fedora advisory for Exercism CLI 3.2.0Memory-issue security advisory against the Exercism CLI package on Fedora 37.
- Polyfill vulnerability discussionCommunity forum thread discussing a polyfill vulnerability affecting the site.
What users say
Users love it as a free practice tool but repeatedly say it's for practicing, not learning to code from scratch.
“Exercism is great and free!”
“Exercism.io isn't for learning to code, but for practicing”
“Exercism is worthy of 120$ a year and worth it”
Alternatives
Compare Exercism with each alternative.
Codecademy
Guided beginner courses if you're starting from zero
Exercism vs CodecademyLeetCode
Interview-prep drilling with company-style problems
Exercism vs LeetCodeCodinGame
Gamified practice puzzles if exercises feel dry
Exercism vs CodinGameW3Schools
Free tutorials with quick in-browser try-it examples
Exercism vs W3SchoolsFull analysis
Based on ~20 public sources: official site, Reddit, Hacker News, Trustpilot, and security advisories. Some snippets were truncated.
Sources
- Exercism homepage — 100% free, 83 languagesexercism.orgofficial
official
review
- Exercism is great and free — Redditreddit.comreview
- 2M users but no money in the bank — Hacker Newsnews.ycombinator.comnews
- Exercism desperately needs Rust mentorsusers.rust-lang.orgreview
- Exercism Teams... Coming soon?forum.exercism.orgreview
- CVE-2025-61723 exercism: Quadratic complexitybugzilla.redhat.comsecurity
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