Marble LeetCode Tutor Chrome Extension
An AI tutor that walks you through any LeetCode problem step by step.
At a glance
Starts at
Free
No paid plan found on the Chrome Web Store, September 2026.
Free tier
Yes
Platforms
Chrome
Best for
Coders practicing for technical interviews
Not for
People wanting practice outside LeetCode
5.0 out of 5
Scored by a Toolio reviewer after real useOur verdict
Marble sits on top of LeetCode and walks you through a problem in three stages: understanding it, planning an approach, then implementing that plan in code, mirroring how a technical interviewer wants to see you think. You start it by clicking a pin on any LeetCode problem page. It's built and maintained by a single developer, though its 23 reviews at a full 5 out of 5 suggest it's holding up well so far.
✓What it does well
Structured problem walkthroughsIt breaks a problem into understanding, planning, and implementation stages.
Interview-style reasoningThe process mirrors how technical interviewers want candidates to think out loud.
Strong early ratingsIt holds a full 5 out of 5 across 23 reviews so far.
✕Where it falls short
LeetCode onlyIt only works on top of LeetCode, not other coding practice sites.
Single-developer projectIt's built and maintained by a single developer rather than a larger team.
Small footprint, small supportSupport runs through a direct email to the developer, with no dedicated help team.
Key features
Interactive walkthroughsIt guides you through a LeetCode problem step by step.
Problem understanding stageIt starts by helping you understand what the problem is actually asking.
Plan-then-code approachIt has you form a plan before writing any code.
Any-language supportIt works with any LeetCode problem in any programming language.