Free Textbooks for Every Course

Every resource listed here is 100% free to read online — no account required, no paywall, no cost. Paired with each OKSTEM course for deeper study.

Trusted Free Providers

OpenStax — free CC college textbooks
CK-12 — free K–12 science & math FlexBooks
MIT OpenCourseWare — free university course materials
Open Up Resources — free K–5 math curriculum
Code.org — free K–12 CS curriculum
Khan Academy — free video + practice for all grades
College — Computer Science
CS Courses (Associate of Science)
CS 101 — Intro to CS
Introduction to Computer Science
OpenStax
CC BY 4.0
Read Free
CS 111 — Python I
6.100L: Introduction to CS & Programming Using Python
MIT OpenCourseWare
MIT OCW
Read Free
Alt: Introduction to Python Programming — OpenStax
CS 112 — OOP
Introduction to Python Programming
OpenStax
CC BY 4.0
Read Free
Alt: OOP in Python — Goldwasser & Letscher
CS 121 — Discrete Math
Discrete Mathematics: An Open Introduction
Oscar Levin (4th Edition)
CC BY-SA 4.0
Read Free
CS 201 — Data Structures
Open Data Structures (in Python)
Pat Morin
CC BY 4.0
Read Free
Alt: Problem Solving with Algorithms & DS — Miller & Ranum
CS 211 — Computer Organization
Introduction to Computer Organization
Robert Plantz
Free Online
Read Free
Alt: OpenStax CS Ch. 5 — Computer Systems Organization
CS 221 — Database Systems
Database Design (2nd Edition)
Adrienne Watt — BC Open Textbooks
CC BY 4.0
Read Free
CS 222 — Operating Systems
Operating Systems: Three Easy Pieces (OSTEP)
Arpaci-Dusseau & Arpaci-Dusseau
Free Online
Read Free
CS 231 — Software Engineering
Software Engineering: A Modern Approach
SE-EDU Initiative
Free Online
Read Free
Alt: SE for Self-Directed Learners — se-education.org
CS 241 — Computer Networks
Computer Networks: A Systems Approach
Peterson & Davie
CC BY 4.0
Read Free
Alt: An Introduction to Computer Networks — Dordal
College — Mathematics
Math Courses
MATH 141 — Calculus I
Calculus Volume 1
Gilbert Strang & Edwin Herman — OpenStax
CC BY 4.0
Read Free
MATH 201 — Statistics & Probability
Introductory Statistics 2e
Barbara Illowsky & Susan Dean — OpenStax
CC BY 4.0
Read Free
K–12 — Grades 3–5
Elementary Courses
Block Coding (3–5)
Scratch — Free Block Coding Platform
MIT Media Lab
Free Online
Open Scratch
Intro to Python (3–5)
Khan Academy — Intro to Python Fundamentals
Khan Academy
Free Online
Read Free
3rd Grade Math
Open Up Resources K–5 Math (Grade 3)
Illustrative Mathematics
CC BY 4.0
Read Free
4th & 5th Grade Math
Open Up Resources K–5 Math (Grades 4–5)
Illustrative Mathematics
CC BY 4.0
Read Free
3rd–5th Grade Science
OpenSciEd Elementary Units (NGSS-aligned)
OpenSciEd
Free Online
Read Free
Engineering Challenges (3–5)
TeachEngineering Grades 3–5 Activities
TeachEngineering / University of Colorado
CC BY-SA
Read Free
K–12 — Grades 6–8
Middle School Courses
Data & Charts with Python (6–8)
Automate the Boring Stuff with Python
Al Sweigart
CC BY-NC-SA
Read Free
Engineering & Systems (6–8)
TeachEngineering Grades 6–8 Activities
TeachEngineering / University of Colorado
CC BY-SA
Read Free
Intro to Python (6–8)
Code.org Python Lab & CS Discoveries
Code.org
Free Online
Read Free
Middle School Math (6–8)
CK-12 Middle School Math FlexBooks
CK-12 Foundation
CC BY-NC-SA
Read Free
Middle School Science (6–8)
CK-12 Life / Earth / Physical Science FlexBooks
CK-12 Foundation
CC BY-NC-SA
Life Science
Earth Science  |  Physical Science
Web Basics (6–8)
Learn to Code HTML & CSS
Shay Howe
Free Online
Read Free
K–12 — Grades 9–12
High School Courses
Advanced Python & APIs (9–12)
Automate the Boring Stuff with Python
Al Sweigart
CC BY-NC-SA
Read Free
Alt: Official Python Tutorial — Python.org
Algebra 1 (9–12)
Algebra 1
OpenStax
CC BY 4.0
Read Free
Database & SQL (9–12)
Database Design (2nd Edition)
Adrienne Watt — BC Open Textbooks
CC BY 4.0
Read Free
Alt: SQL Notes for Professionals — Goalkicker
Financial Literacy (9–12)
Khan Academy Financial Literacy
Khan Academy
Free Online
Read Free
Geometry (9–12)
CK-12 Interactive Geometry (CCSS)
CK-12 Foundation
CC BY-NC-SA
Read Free
Linear Algebra (9–12)
Understanding Linear Algebra
David Austin
CC BY 4.0
Read Free
Alt: A First Course in Linear Algebra — Beezer (CC BY)
Advanced Math (9–12)
Algebra and Trigonometry 2e
OpenStax
CC BY 4.0
Read Free
High School Science (9–12)
CK-12 Biology / Chemistry / Physics FlexBooks
CK-12 Foundation
CC BY-NC-SA
Read Free
Biology 2e — OpenStax  |  Chemistry 2e — OpenStax
Systems Engineering & CS (9–12)
MIT OCW — Introduction to Computer Science & Programming
MIT OpenCourseWare
MIT OCW
Read Free
Full-Stack Web Development (9–12)
The Odin Project — Full Curriculum
The Odin Project (open source)
CC BY-NC-SA
Read Free
Alt: Eloquent JavaScript — Marijn Haverbeke (CC BY-NC)
K–12 — Kindergarten–Grade 2
Early Learner Courses
Digital Safety & Citizenship (K–2)
Common Sense Education — Digital Citizenship Curriculum
Common Sense Education
Free Online
Read Free
K–2 Engineering
DiscoverE K–2 STEM Activities
DiscoverE
Free Online
Read Free
K–2 Math
Khan Academy Kids
Khan Academy
Free Online
Read Free
Alt: Open Up Resources K–5 Math (CC BY)
My First Code (K–2)
Code.org Course A — Pre-K & Kindergarten
Code.org
Free Online
Read Free
K–2 Science
OpenSciEd K–2 Units (NGSS-aligned)
OpenSciEd
Free Online
Read Free
What Is a Computer? (K–2)
Code.org Pre-Reader Express Course
Code.org
Free Online
Read Free
All resources on this page are 100% free. No account, no credit card, no paywall. Resources marked CC are published under a Creative Commons license — you can read, download, and share them freely. Resources marked Free Online are provided gratis by their publishers (OpenStax, Khan Academy, MIT, Code.org, etc.).