Learn C# and .NET, properly — 315 free lessons
A complete written course that takes you from your first line of C# through to running .NET in production. No signup, no paywall, no video to sit through — just lessons you can read, search, and come back to.
C# Foundations
59 lessons · 7 parts · about 22 hours
Start here if you have never written C#. Syntax, types, control flow and object-oriented programming, built up one concept at a time with nothing assumed.
C# In Practice
90 lessons · 8 parts · about 32 hours
The idioms a working .NET developer uses every day — generics, collections, LINQ, async and await, dependency injection, data access and testing.
Production .NET
166 lessons · 13 parts · about 64 hours
How .NET behaves under real load: language internals, memory and performance, architecture, distributed systems, cloud deployment, security, observability and production debugging — closing with a full capstone build.
Guides and references
Start HereA week-by-week roadmap, whether you are brand new to programming or switching to .NET from another language.
.NET RoadmapEverything a .NET developer needs to learn, in order, with the time each stage takes and a lesson for every skill.
Interview PrepSixty C# and .NET interview questions with direct answers, each linked to the lesson that goes deeper.
C# Cheat SheetThe syntax you reach for every day on one page, current to C# 14 and .NET 10.
GlossaryEvery C# and .NET term defined in plain English, with a link to the lesson that explains it.
Full SyllabusAll 315 lessons on one page, grouped by tier and part, with the reading time for each.
How to use this course
Pick any lesson from the sidebar and it opens right here. Your progress is remembered in your own browser — nothing is sent anywhere, and there is no account to create. Use the search box to jump straight to a topic, or open the full contents to see the whole syllabus at once.
Every lesson shows its reading time (most are 15 to 25 minutes), the sidebar shows how much of each part is left, and every lesson ends with a short quiz you answer in place, with instant feedback. Finish a lesson a day and you will see your streak grow.
Every lesson also lives at its own address, so you can bookmark one, share it, or read it on its own without the course player around it.
On mobile, tap the menu icon in the top-left to open the lesson list.