A free ChemDraw alternative that runs in your browser
Free AI chemical structure editor · no install · no account needed
ChemDraw is the standard for chemists, but a licence costs hundreds of dollars a year and it is a desktop program. If you need a correct 2D structure for a report, a slide, a homework set or a patent sketch, MolChart does the job for free, online, and with a different workflow: you tell it what to draw.
ChemDraw vs MolChart
| ChemDraw | MolChart | |
|---|---|---|
| Price | Paid licence | Free; optional $10/month membership |
| Runs | Desktop (Windows/Mac) | Any browser, nothing to install |
| Drawing | Manual tools (bonds, rings, templates) | Plain-English instructions, names or SMILES – AI draws and verifies; manual bond, ring and element tools too |
| Verification | Manual | Automatic valence check + PubChem comparison |
| Naming | Struct=Name | Structure → IUPAC name and name → structure |
| Export | CDX, PNG, SVG, MOL… | PNG, SVG, SMILES, MOL |
| NMR prediction, templates, biopolymers | Yes | No |
Where MolChart fits
- Students and teachers – draw and check structures quickly, see stereochemistry, get the IUPAC name.
- Writers, patent and regulatory staff – a correct structure image without learning a drawing program.
- Chemists away from their desk – works on a phone or tablet.
- AI assistants – MolChart is available as a ChatGPT app and an MCP server.
Other free options
Other free manual editors are MarvinSketch, ChemSketch and Ketcher. MolChart gives you both: describe the molecule when that is faster, and reach for the bond, ring and element tools when it is not.
Try it: draw paracetamol · draw the Diels–Alder reaction of butadiene and ethylene · draw (R)-ibuprofen and name it
Frequently asked questions
Can MolChart open ChemDraw (.cdx / .cdxml) files?
Not directly. Export your structure from ChemDraw as a MOL file or copy it as SMILES and import that.
Does it produce publication-quality images?
It exports SVG (vector) and PNG. Bond lengths, angles and fonts follow common journal conventions; you can resize the SVG without loss.
Does it do reactions?
Yes – reaction arrows, reagents above the arrow, and text labels. The assistant understands what is on each side of an arrow.
Is there a catch?
No. Drawing, exporting and analysis are free. AI assistant use is metered on the free tiers; a $10/month membership makes it unlimited.