Getting Started
Welcome to ChemStitch
ChemStitch is a web-native chemical structure editor with built-in AI. Draw molecules, ask the AI about them — properties, reactions, retrosynthesis, naming — all in your browser.
The AI chat panel sits alongside the structure editor. Draw a molecule on the canvas and the AI sees it in real time. Ask about properties, predict reactions, plan synthetic routes, or look up compounds in PubChem — without switching tools.
Creating an account
ChemStitch offers a free 14-day trial — no credit card required. Enter your email on the landing page or login page and we’ll send you a sign-in link.
On the login page, enter your email and click Send sign-in link. If your email is registered, we’ll send a magic link to your inbox — click it and you’re taken straight to the editor. No password required.
New here? Just enter your email — your trial starts the moment you click the link. The trial banner in the editor shows how many days you have left.
Drawing your first molecule
The editor opens with an empty canvas. You can start drawing immediately using the bond tools in the toolbar, or use a quick-start template — click one of the starter molecules (benzene, aspirin, caffeine) to load a structure onto the canvas.
Use keyboard shortcuts for fast editing: press 1, 2, or 3 to switch between single, double, and triple bonds. Press R to open ring templates. Press ? to see all available shortcuts.
Your first AI interaction
With a molecule on the canvas, type a question in the chat panel. The AI sees your current structure automatically — no need to copy or describe it.
Try: "What are the properties of this molecule?" The AI calls RDKit to compute molecular weight, logP, hydrogen bond donors and acceptors, topological polar surface area, rotatable bonds, and drug-likeness (Lipinski Rule of Five evaluation).
Property results are displayed with confidence indicators: Computed (green, deterministic via RDKit) for calculated values, and AI Suggested (yellow) for predictions that should be verified experimentally.
Document management
Your work auto-saves to the cloud. The save indicator in the header shows Saved, Saving, or Error.
From the documents page, you can create new documents, rename existing ones, and delete documents you no longer need. Each document preserves the canvas state and full chat history.