AI-powered coding tutor
Don't just fix your code.Learn why it's wrong.
An AI-powered coding tutor that helps you understand your mistakes instead of simply giving you the answer.
The CodeLens loop
Solve
Pick a Python problem and write your attempt.
Get a hint
CodeLens spots likely misconceptions and nudges gently.
Understand
Read a concept-level explanation of why the mistake happens.
Try again
Apply the insight in your next attempt.
Improve
Difficulty adapts to your real performance over time.
Not another answer machine
Typical assistants hand you working code — you copy it, learn nothing, and hit the same wall tomorrow. CodeLens is built the other way around: it diagnoses the misconception behind your mistake, gives progressive hints, and only explains deeply when you ask. You always write the solution yourself.
- ✓ Progressive hints that never spoil the answer
- ✓ Concept-level explanations, not code dumps
- ✓ Honest analysis — your code is reviewed statically, never executed
17 curated Python problems
From first functions to binary search — organized by difficulty, tagged by concept, with adaptive recommendations based on your real track record stored privately in your browser.