Draw the mechanism. Get every step marked.
Mechanism practice where you push the electrons yourself - marked step by step, not just right or wrong. 194 expert-verified problems across 39 subtopics.
3 problems graded free. $12/month for the rest, cancel anytime.
Works in any browser. Feels like paper with a stylus on a tablet.
tert-Butyl bromide is warmed in methanol. Draw the mechanism.
Then find out what you keep getting wrong
Every step you draw is marked, so the platform learns your patterns and tells you what to focus on.
Your mechanistic insights
Across every mechanism you've drawn, deprotonation is where you lose the most - 3 of 5 missed.
Counted across subtopics, so a step you always miss shows up here even when your topic scores look fine. Drawn mechanisms only - multiple choice isn't included.
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: draw bonds, lone pairs, charges, radicals and more. Best with a stylus on a tablet, fine with a mouse.
Get graded step by step
Every step of your mechanism comes back marked, just like an examiner would.
A canvas built for mechanisms, not just checkboxes
You can't guess an arrow
Multiple choice lets you eliminate your way to an answer you couldn't have produced. A blank canvas doesn't - you either know where the electrons go, or you find out that you don't.
Marked like an exam, not a quiz
Your mechanism comes back step by step, so a right product reached by a wrong route doesn't pass - and one bad step doesn't wipe out the four you got right.
Practice at the actual task
Your midterm asks you to draw the mechanism. This is practice at doing that, rather than at recognising it in a list of four options.
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
- ✓3 hand-picked problems, free to try
- ✓Graded step by step, with a second go at each after the feedback
- ✓Multiple choice with full explanations
- ✓No card required
Subscription
$12/month
or $40 every 4 months - $10.00/month, save 17%
- ✓All 194 problems, across every subtopic
- ✓Step-by-step feedback on every drawing, up to 300 graded in any 30-day period
- ✓Progress tracking across every subtopic
- ✓New problems added regularly, cancel anytime
Nothing reaches you unchecked
Problems are drafted with AI, then expert-verified line by line before they are published. Nothing reaches you until the mechanism, the arrows and the explanation have all been checked by a chemist.
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.
Questions worth asking first
- Is this just multiple choice?
- No. Mechanism problems have you push the arrows yourself on a canvas that takes bonds, curly arrows, lone pairs, charges and radicals, and every step you draw is marked. Others ask you to draw the product. Topics with nothing to draw, like R/S assignment, NMR and pKa, are multiple choice with full explanations - but drawing mechanisms is what it is built around.
- Can I use it on a tablet?
- Yes - it is built for one. Draw with a stylus the way you would on paper, and bonds, curly arrows and lone pairs go down in quick strokes. It runs in the browser on any tablet, laptop or desktop, and a mouse or trackpad works too.
- Will it match my course?
- It is written to the standard of a college midterm or final rather than to one textbook, covering SN1/SN2, E1/E2, Grignards, acyl substitution, aldols and aromatics across the Orgo I and II syllabus.
- What happens when I get a step wrong?
- You are told which step broke and why, then you get a second go at it after the feedback. Across sessions the platform tracks the kinds of step you keep missing - deprotonation, nucleophilic attack, leaving group departure - so you know what to drill.
- Who checks the chemistry?
- Problems are drafted with AI and then expert-verified line by line before they are published. The grading of your drawing is done by AI, so it can be wrong - it is built to make you better at mechanisms, not to replace your course.
- Do I need a card to try it?
- No. 3 problems are graded free without one, so you can see whether it is any good before spending anything.
- Is there a limit on grading?
- A subscription covers up to 300 graded drawings in any 30-day period, which is about ten a day. Multiple choice and reading explanations are uncapped.
Stop recognising mechanisms. Start drawing them.
3 problems graded free, no card required. $12/month for the rest.
Try one free - no sign-up →