What molecule formats does this editor support?

The editor supports SMILES notation input, MOL V2 and V3 file import/export, RXN reaction files, SVG vector graphics export, and PNG image download. You can also copy IDCode format used by OpenChemLib.

Can I draw chemical reactions, not just molecules?

Yes. Click the Reaction button in the editor header to switch to reaction mode. You can draw reactants, products, and catalysts, add atom mapping, and export as reaction SMILES or RXN files.

Is this molecule editor free and does it work offline?

Yes, it is completely free with no registration or login required. The editor runs 100% in your browser using the OpenChemLib library loaded from CDN. After the initial load, all drawing and calculations happen client-side with no data sent to any server.

Molecule Draw - Free Online Molecular Structure Editor

Preview

Draw a molecule to see preview

Properties

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Formula

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Mol. Weight

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Atoms

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Bonds

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Rings

Render Options

Display

Inflate to max avg bond length Inflate high resolution Show atom numbers Show bond numbers Show mapping Show simple symmetries Show all symmetries Show stereo-heterotopicity

Suppress / Hide

Suppress chiral text Suppress CIP parity Suppress ESR Hide implicit hydrogens Disable atom label colors Disable stereo problems Disable CIP/ESR coloring Hide custom labels

Chiral Text Position

Below molecule Above molecule Top of frame Bottom of frame

Style

Bonds in gray Auto-crop whitespace No tabus Highlight query features

SMILES

MOL File

Reaction

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Reactants

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Products

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Catalysts

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Mapped

Molecule Draw

Input

Structure Editor

Output

Preview

Properties

Render Options

SMILES

MOL File

Reaction

Reaction SMILES

Export

Keyboard Shortcuts

Input

Structure Editor

Output

Preview

Properties

Render Options

SMILES

MOL File

Reaction

Reaction SMILES

Export