What is Open Free Books?
Open Free Books aims to be more than a learning resource: free textbooks for everyone worldwide, from elementary school through university — on the web, at no cost.
We aim to cater to different syllabi and curricula across the globe. It is a community effort by educators and contributors around the world, built in the open on GitHub.
Free means the whole book for everyone: read online without paywalls or premium unlocks. Open means anyone can fix a typo, add a chapter, or fork a book for a classroom.
How is Open Free Books different from LibreTexts, Open Textbook Library, Project Gutenberg, and OpenStax?
We respect these projects — they solve different problems. On many platforms, you find lots of different books for a single subject. With Open Free Books, there's just one textbook per subject—designed to be comprehensive so people everywhere can use it for any curriculum. That way, you don't need to pick between competing choices—you can just focus on learning. Also these platforms usually only provide static HTML without any interaction or just PDFs, but in OpenFreeBooks we have interactive demos and knowledge maps that are tailor made to visualize complex idea in simple ways.
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Open educational resource platform with broad textbook collections and institutional adoption.
Open Free Books is a focused open textbook library with curriculum-shaped pathways, lightweight static delivery, and contributor-driven book structure.
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A catalog and discovery hub for openly licensed textbooks with reviews and adoption support.
Open Free Books publishes and maintains textbooks directly in the open repository, including chapter sequencing and prerequisite maps.
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A public library of free eBooks, especially classic works and historical texts.
Open Free Books is built for active learning: modern textbook chapters, guided progression, and curriculum alignment rather than archival eBook distribution.
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Peer-reviewed open textbooks for major school and college subjects.
Open Free Books emphasizes community-authored web textbooks with transparent GitHub workflows and adaptable chapter-level contribution.
Open Free Books — Free forever, no ads, no commercial upsell, and open on GitHub for anyone to fix or extend.
Is it really free? Will there be ads or paid tiers?
Yes — free is the product, not a trial. Every book and chapter is readable without a subscription or premium unlock.
Open Free Books offers no commercial services and no ads, now or in the future. Sustainability comes from community contribution and shared open infrastructure, not from turning learners into the product.
What does "open" mean? How do I contribute?
Open means the textbooks are built in public on GitHub. You can read the source, open a pull request, fork for your syllabus, and see every change in version control.
To add or improve material, start with the contributing guide on this site or open a discussion or pull request on GitHub. You do not need permission from a publisher.
Contributing guide
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GitHub repository
How is this different from commercial textbook platforms?
Many commercial platforms sell access, host ads, or bundle paid services around "digital" textbooks. Content may be locked behind logins, and terms can change when a vendor updates its product.
Open Free Books is non-commercial: no paywalls, no ad network, no investor-driven upsell. Books are static HTML in an open repository — readable in a browser today, forkable for your classroom tomorrow.
Does Open Free Books replace teachers?
No. A great teacher still sets pace, asks hard questions, and notices when a student is stuck. That relationship is not what we are trying to automate.
Textbooks are reference and structure: explanations, exercises, diagrams. Those can be free, forkable, and kept current on the web so teachers spend less time hunting permissions and more time teaching.
Why web pages instead of PDFs?
Paper and most "digital" textbooks are fixed layouts — hard to search, hard to update, and poor homes for live diagrams or interactives.
HTML on the open web can link to sources, resize for any screen, embed simulations, and improve over time. The book becomes something you use, not a file you download once.
Is the content AI-generated?
We use AI as a drafting and editing tool, but we do not rely on AI chat tokens as the final product layer. We publish reviewed, hand-curated chapters as open HTML so learning materials stay readable without paid AI access.
Token costs matter. Today some companies appear to offer "free" AI access, but that is often market-share strategy in an early stage. If prices rise later, learners with less money or weaker infrastructure could lose access.
The open web is more durable: HTML and JavaScript are stable foundations likely to remain usable for decades. Building high-quality, future-proof educational materials now — with AI assistance but web-native outputs — is the practical long-term approach.
Why isn’t the content perfect?
No textbook is perfect — whether it’s a PDF, a printed book, or an online resource. Learning evolves, and so does our understanding of what makes content useful and accurate.
Open Free Books may not be flawless, but it’s built on lasting web standards: HTML, JavaScript, and CSS. This means chapters are readable on any device, by anyone, anywhere — making them among the most accessible textbooks in the world.
We set high standards for academic quality, and the catalog is always improving. Every chapter is open for review and enhancement by contributors, so progress never stops.
What are curriculum labels on the catalog?
Each subject in the catalog has a set of curricula you can filter by — exam boards, school programs, and similar labels — so you can see which chapters fit your syllabus. For Mathematics, the Compare tab documents how frameworks differ and how chapters map to them.
We try to keep chapter structure and prerequisite maps compatible with as many curricula as possible. We do our best, but coverage is not perfect; the catalog will grow and improve as more people contribute.
Those labels appear only in the catalog (badges and filters), not inside chapter pages. You choose what applies to you on the catalog; inside a chapter, the focus stays on the topic itself.
Browse the catalog
How do I find a chapter?
Open the catalog for a subject — list view by default, map view for prerequisites, or (for Mathematics) Compare for how popular curricula relate to our chapters. Use curriculum filters on list and map if you need to narrow the list.
Press ⌘K or Ctrl+K (or open Search in the header) to search live chapter pages. The dedicated search page indexes chapter content, not every site page.
Browse the catalog
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Search chapters
Where are the project principles?
The About page (Manifesto) lists the values we will not trade away as the catalog grows: free, open, curriculum-shaped, independent, durable, crafted, inspectable, and web-native.
Read the manifesto for the full principles behind every book on this site.
Read the manifesto