Draw the mechanism. Find out which step you got wrong.
Mechanism practice where you push the electrons yourself. Sketch the curved arrows in the browser and every step comes back marked — not one right-or-wrong verdict on the final answer. 79 expert-verified problems across 22 subtopics, each one reviewed by a PhD organic chemist before it reaches you.
4 problems and 3 graded drawings free. $15/month for the rest.
tert-Butyl bromide is warmed in methanol. Draw the mechanism.
How it works
Pick a mechanism
SN1/SN2, E1/E2, Grignards, aldols, aromatics — the reactions your midterms are actually built from.
Draw the arrows
Push electrons on a canvas built for chemistry: snapping bonds, stamped rings, and atom labels straight from the keyboard.
Get graded step by step
Not a right/wrong verdict. Every step of your mechanism comes back marked, so you find out which arrow went the wrong way.
A canvas built for mechanisms, not just checkboxes
Everything you need to get a mechanism out of your head and onto the page, and nothing you have to learn first.
Pen
Freehand arrows and structures — exactly what your hand would do on paper.
Bond
Drags out to proper 30° skeletal angles, so structures come out clean without a steady hand.
Ring
Click to stamp a benzene ring, or drag to size it. No more hand-drawn hexagons.
Erase & undo
Rub out any stroke, or undo your last one. Nothing you draw is permanent.
Move
Grab anything you've drawn and reposition it, instead of starting the structure over.
Atom labels
Type a letter to drop a heteroatom where your cursor is. Scroll to zoom in on the fiddly bits.
Try it before you pay for it
Sign up and start drawing straight away. No card until you decide it's worth it.
Free
$0
- ✓4 problems from SN1 vs SN2 and E1 vs E2
- ✓3 drawings graded step by step
- ✓Multiple choice with full explanations
- ·No card required
Subscription
$15/month
- ✓All 79 problems, across every subtopic
- ✓Unlimited step-by-step drawing feedback
- ✓Progress tracking across every subtopic
- ✓New problems added regularly, cancel anytime
Nothing reaches you unchecked
Problems are drafted with AI, then reviewed line by line by a PhD organic chemist before publishing. A study tool that confidently teaches you the wrong mechanism is worse than no study tool, so nothing is published on the model's say-so alone.
Built for your actual exams
SN1/SN2, E1/E2, Grignards, acyl substitution, aldols, aromatics and more — written to the standard of a college midterm or final rather than shallow trivia. Solid MCAT preparation too.