Teach modern web development with real code.

Interactive TypeScript exercises, GitHub projects, and student progress in one place.

Free plan: one course, up to 30 students. No credit card required.

Explicit vs Inferred

Give the variable score an explicit number type annotation.

For teachers

Use Codington for browser exercises, GitHub projects, and student progress.

For learners

Practise TypeScript in your browser with focused exercises and instant feedback.

For programming teachers

Bring browser exercises, real GitHub projects, submissions, feedback, and student progress into one place.

For TypeScript learners

Build real understanding with focused browser exercises and instant feedback. No account required.

TypeScript builds on JavaScript by adding types, so we can describe exactly what kind of values a variable

Functions are how we structure behavior. In TypeScript, you can describe parameter types and return types so

Objects model real-world entities. In TypeScript, you describe an object's shape by listing its properties

Free plan

Create a complete course with TypeScript exercises, GitHub assignments, progress, feedback, and grades. No credit card required.

Codington combines a teaching workspace with free browser-based TypeScript practice.