Four places to start
The subjects that change what you can do.
Numbers, money, reasoning, and running something of your own. Each subject is a path of short lessons that builds level by level — open any course below and begin, no account needed.
- Pre-K to university38 levels
Mathematics
From counting and comparing to algebra, calculus, probability, and university analysis. The longest path on the platform, and the foundation under the other three.
- Early mathematics A — Mathematics (opens in a new tab)Pre-K
- Fractions, level 3 — Mathematics (opens in a new tab)Around grade 3
- Mathematics level 7 — Mathematics (opens in a new tab)Around grade 7
- Algebra I — Mathematics (opens in a new tab)Secondary
- Statistics and probability — Mathematics (opens in a new tab)Secondary
- Calculus BC — Mathematics (opens in a new tab)Secondary
- Money and choices6 levels
Economics
Why there is never enough of everything, and what people do about it: scarcity and trade-offs, markets and prices, up to intermediate micro- and macroeconomics.
- Wanting more than there is — Economics (opens in a new tab)Around grade 3
- Scarcity, choice and trade-offs — Economics (opens in a new tab)Around grade 6
- Markets, prices and money — Economics (opens in a new tab)Around grade 8
- Microeconomics — Economics (opens in a new tab)Advanced
- Macroeconomics — Economics (opens in a new tab)Advanced
- Intermediate economics — Economics (opens in a new tab)Advanced
- Thinking clearly8 levels
Logic & Philosophy
How to tell a good reason from a bad one. Claims and arguments, weighing evidence, formal and symbolic logic, then ethics, knowledge, and the mind.
- Reasons and claims — Logic & Philosophy (opens in a new tab)Around grade 5
- Arguments in the wild — Logic & Philosophy (opens in a new tab)Around grade 7
- Reasoning about evidence — Logic & Philosophy (opens in a new tab)Around grade 8
- Formal logic — Logic & Philosophy (opens in a new tab)Advanced
- Ethics — Logic & Philosophy (opens in a new tab)Advanced
- Mind and metaphysics — Logic & Philosophy (opens in a new tab)Advanced
- For people running one5 levels
Small Business
The practical side of keeping a small business alive: costs, pricing and break-even, cash, customers and sales, operations and people, strategy and risk.
- Costs, pricing and break-even — Small Business (opens in a new tab)
- Money, costing and cash — Small Business (opens in a new tab)
- Customers and sales — Small Business (opens in a new tab)
- Operations and people — Small Business (opens in a new tab)
- Strategy, growth and resilience — Small Business (opens in a new tab)
And more
More subjects, all of them free.
The same step-by-step lessons reach into the sciences, history, geography, and study skills. Every subject is free — browse any of them.
- History (opens in a new tab)
- Geography (opens in a new tab)
- Physics (opens in a new tab)
- Chemistry (opens in a new tab)
- Earth, Space & Astronomy (opens in a new tab)
- Memory & Cognitive Skills (opens in a new tab)
How it works
Choose. Learn. Build.
Pick a subject and a level that feels comfortable — the levels describe topics, not placement, so you can move up or down any time. Work through short guided lessons at your own pace, and create a free account only when you want your progress saved.
- Every course, every subjectFree, always
- Browsing and lessonsNo email needed
- Private progressWith a free account
- PaceYours — no deadlines
- Interface languages8
Younger learners have a separate child sign-in of their own.
Plainly
Free learning, with no catch.
There is nothing to buy and no trial that runs out. Nydus Open Learning is run by Nydus Foundation, a nonprofit, and it is paid for by donations.
It is not a school: it does not award diplomas or academic credit, and it is not a substitute for compulsory schooling. It is a place to learn.
Keep discovering
Let a good question lead somewhere new.
The Nydus Foundation Library is full of free books to read, download, and share. Find a fresh perspective, follow an interest beyond a lesson, or simply enjoy the next page.
Browse the Library