WAVESPEED AI STRUCTURE DRAWER Structures stay on your device

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Free Chemical Structure DrawerDraw it, check it, export it, see it in 3D.

Draw molecules with bonds, rings, wedges, charges and isotopes, or paste a SMILES or molfile.
Get the formula, exact mass, logP, TPSA, H-bond counts, R/S labels and Lipinski's rule of five as you draw, export publication-quality images and structure files, and open proteins and small molecules in 3D.

Files stay on your deviceSMILES · MOL · SDF · InChI2D editor + 3D viewer

No sign-up No upload Nothing to install

Loading the structure editor…

Drawings and files are processed in your browser and never uploaded.The chemistry engine downloads once (about 3 MB) and is then cached.

THREE SIMPLE STEPS

How to draw a chemical structure online

Draw or paste

Click to place bonds and drag to aim them, add rings and groups, type element letters over atoms, or paste a SMILES or molfile. Open MOL and SDF files too.

Check the chemistry

The panel shows the formula, masses, logP, TPSA, H-bond donors and acceptors, Lipinski's rule of five, R/S labels and canonical SMILES, InChI and InChIKey. Atoms with too many bonds are marked in red.

Export or view in 3D

Download PNG or SVG images for papers and slides, MOL, SDF, SMILES or InChI files, or build a 3D model and rotate, measure and save it.

What you can do

A real structure editor

Bonds of every order with wedges and hashes, ring templates that fuse onto bonds, functional groups, charges, isotopes and radicals, rubber-band selection, rotate and flip, merge atoms, and one-click clean-up of the layout.

Properties as you draw

Molecular formula, average and exact mass, elemental composition, Crippen logP and molar refractivity, TPSA, H-bond donors and acceptors, rotatable bonds, ring counts and fraction sp³ update with every edit.

Identifiers and files

Canonical SMILES, CXSMILES, standard InChI and InChIKey, MOL V2000 and V3000, and SDF with data fields. Paste SMILES or molfiles, open SD files with many structures and pick one.

Publication images

Clean SVG and high-resolution PNG drawings in colour or black and white, with optional R/S labels and a transparent background, or copy the image straight into a document.

3D viewer for proteins

Open PDB and mmCIF files: cartoon, ball and stick, space-filling or surface; colour by chain, residue, secondary structure or B-factor; click residues in the sequence, label them and measure distances, angles and dihedrals.

From drawing to 3D

Turn any drawing into a 3D model that keeps its stereochemistry, relaxed with the MMFF94 force field, then view it, measure it or download it as SDF.

WaveSpeed AI

Make visuals for your chemistry.

Turn molecules into illustrations, cover art and explainer clips for slides, papers and lessons with WaveSpeed AI.

Start creating Explore 1,000+ AI Models

1,000+ AI models
Image, video and 3D
Pay as you go

$1 in free credits for eligible new accounts. No card needed. Generators have separate account and credit requirements. The structure drawer is free.

Chemical structure drawer FAQ

Is this structure drawer free?

Yes. Draw, analyse and export as much as you like, with no account, no watermark and no limits.

Are my structures uploaded?

No. Drawing, calculations, file reading and 3D models all run in your browser. The chemistry engine and the 3D viewer are downloaded once from a public code library; your structures and files are never sent anywhere.

Which files can I open and save?

The 2D editor reads SMILES, MOL (V2000 and V3000) and SDF files and saves PNG, SVG, MOL, SDF, SMILES, CXSMILES and InChI. The 3D viewer opens PDB, mmCIF, SDF, MOL, MOL2 and XYZ files and saves PNG images and 3D SDF files.

Can I paste an InChI or a chemical name?

Not yet. InChI and InChIKey are calculated for every structure, but turning an InChI or a name back into a structure isn't supported here. Paste SMILES or a molfile instead; most databases offer both.

How are logP, TPSA and the H-bond counts calculated?

With the RDKit cheminformatics toolkit: Crippen's atom-contribution logP and molar refractivity, Ertl's topological polar surface area (N and O only) and RDKit's H-bond donor and acceptor definitions. Values match RDKit's own results for the same structure.

Which definition does the Lipinski check use?

Lipinski's original one: molecular weight up to 500, logP up to 5, at most 5 N–H and O–H groups and at most 10 nitrogen and oxygen atoms. A compound with more than one violation is unlikely to be orally active; it's a guide, not a rule.

How does the 3D model work?

Your drawing, with its stereochemistry, is turned into several 3D shapes from a library of preferred torsion angles; each is relaxed with the MMFF94 force field and the lowest-energy one is shown. It's a good single conformer for viewing and teaching, not a full conformational search.

Can I open proteins from the Protein Data Bank?

Yes. Download a PDB or mmCIF file from a structure database and open it here. The viewer shows cartoons, ligands, surfaces and the sequence, and measures distances, angles and dihedrals. Very large assemblies (hundreds of thousands of atoms) may be slow on phones.

What doesn't it do?

It doesn't convert names or InChI to structures, draw reactions or arrows, predict NMR spectra or pKa, or search databases. It is a structure editor with properties, identifiers, export and 3D viewing.

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