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MolDraw
MolDraw is a browser editor for chemical structures, reaction schemes, mechanisms, and publication figures.
Free with paid plans. 59 of 65 checklist features confirmed.
Official demo
Main canvas
Default drawings
Caffeine
Paclitaxel
Cholesterol in 3D
- Caffeine appeared with aromatic circles in the default SMILES layout.
- Paclitaxel default 2D layout contained overlapping bonds.
- Paclitaxel displayed SMILES differed from input at one stereocenter; connectivity matched.
- Cholesterol 3D bonds appeared elongated in headless Chromium, including after SDF import.
- Downloads and Copy SMILES prompted for an account; molecule details displayed SMILES.
- Current paclitaxel SMILES layout overlapped; MOL import displayed a clear drawing.
- A later cholesterol SMILES import produced a normally proportioned, rotatable 3D model.
- Publisher homepage application metadata declares softwareVersion 4.0.
- Paclitaxel remained stretched at 5, 30, 60 and 120 seconds; UFF stayed 24338.7 kcal/mol.
- Headed Chrome also showed stretched paclitaxel with UFF 24338.7 kcal/mol.
- Cholesterol headless model stayed normally proportioned at 5, 30, 60 and 120 seconds; UFF stayed 63.3 kcal/mol.
- Headed Chrome cholesterol model remained stretched, with UFF 115.2 kcal/mol unchanged over the comparison.
- Original paclitaxel SMILES overlapped through toolbar but drew cleanly through canvas paste.
- Canvas and command-palette imports displayed no stereochemical wedges for paclitaxel.
- Stereo-free paclitaxel produced a clean toolbar layout.
Facts
- Version we tested
- 4.0
- Runs on
- macOS, Windows, Linux, Browser, iOS, Android
- License
- Free core drawing with paid Pro features; not open source.
- Price
- Free tier; Pro US$99/year including tax (2026-11-05; country pricing varies).
- Plans
- Free: US$0 (2026-11-06); Free account: US$0 (2026-11-06); Pro: US$12/month or US$99/year, tax included (2026-11-06)
- Relies on
- Indigo, OpenChemLib. Custom canvas; Indigo optionally supplies 2D layout; OpenChemLib handles structure processing.
- Main language
- JavaScript
- Other languages
- C++: Indigo WebAssembly chemistry; Java: OpenChemLib transpiled 3D chemistry; GLSL: 3D WebGL2 shaders
- Renderer
- Original: In-house Canvas 2D molecule renderer
- Third-party licenses
- Includes Apache-2.0 (Indigo), BSD-3-Clause (OpenChemLib), and OFL-1.1 fonts (Libre Franklin; font derivatives retain OFL).
- Saving or exporting drawings containing Templates content or lab apparatus requires Pro.
- Office editing requires reopening the exported picture in MolDraw and replacing it.
- Free users are asked to credit MolDraw; Pro removes this request.
- Result depends on how SMILES goes in. Pasting on the canvas gave a clean paclitaxel with no wedge or hash bonds shown. The Paste SMILES button kept wedges, but the layout overlapped.
In use
Screenshots from our test of this version.
Single, double and triple bonds
Single, double, and triple bonds on the drawing canvas.
Wedge, hash and wavy bonds
Wedge, hashed wedge, and wavy bonds on the canvas.
Dative, hydrogen and quadruple bonds
Bond menu listing dative and hydrogen bonds.
Ring tools
Benzene and cyclopentane rings on the canvas.
Chair and Haworth rings
Cyclohexane menu with chair and boat options.
Template library
Structure library showing amino acid templates.
Charges, isotopes and atom labels
Structure with element labels and charged atoms.
Radicals and lone pairs
Lone-pair dots appear on oxygen and nitrogen atoms.
Reaction arrows
Arrow menu listing straight, equilibrium, and retrosynthetic arrows.
Curved mechanism arrows
Equilibrium and curved electron-flow arrows on the canvas.
Machine-readable reactions
SMILES paste field shows an example reaction SMILES.
Formula and mass
Caffeine molecule details show formula and molecular weight.
Property estimates
Molecule details show calculated logP and other properties.
Structure to name
Caffeine molecule details show its IUPAC name.
3D model view
Cholesterol drawing beside its three-dimensional model.
CDXML import and export
Download menu lists CDXML among chemistry formats.
CDX import and export
Download menu lists CDX among chemistry formats.
MOL and SDF
Download menu lists the MOL chemistry format.
SMILES
Caffeine molecule details display a SMILES string.
InChI
Caffeine molecule details display an InChI string.
RXN files
Download menu lists RXN among chemistry formats.
SVG export
Download menu lists SVG among image formats.
PDF export
Download menu lists PDF among image formats.
Features
- Tested by running it
- Seen in the app
- The manual says yes
- Partly, with the reason shown
- Not supported
- Not established, which is not the same as no
Select a mark for its proof. A filled mark opens our screenshot, or the manual if the check left nothing to picture. A ring opens the manual.
Drawing structures
- Yes, tested by running it: Drew single, double, and triple bonds. Opens the screenshot.Single, double and triple bondsDrew single, double, and triple bonds.moldraw.com
- Yes, tested by running it: Drew wedge, hashed wedge, and wavy bonds. Opens the screenshot.Wedge, hash and wavy bondsDrew wedge, hashed wedge, and wavy bonds.moldraw.com
- Yes, according to the manual: Dative, hydrogen, centroid, and query bonds are drawable. Opens the cited page.Dative, hydrogen and quadruple bondsDative, hydrogen, centroid, and query bonds are drawable.moldraw.com
- Yes, according to the manual: Repeated clicks or 2 cycle centered, right, and left. Opens the cited page.Choose double-bond sideRepeated clicks or 2 cycle centered, right, and left.moldraw.com
- Yes, tested by running it: Placed benzene and cyclopentane rings. Opens the screenshot.Ring toolsPlaced benzene and cyclopentane rings.moldraw.com
- Yes, according to the manual: Cyclohexane menu offers chair and boat projections. Opens the cited page.Chair and Haworth ringsCyclohexane menu offers chair and boat projections.moldraw.com
- Yes, according to the manual: Drag a zigzag chain; numbered atoms show its length. Opens the cited page.Chain toolDrag a zigzag chain; numbered atoms show its length.moldraw.com
- Yes, tested by running it: Placed alanine from structure library. Opens the screenshot.Template libraryPlaced alanine from structure library.moldraw.com
- Not establishedSave your own templates
- Yes, according to the manual: Ph, Boc, OMe, and other groups expand into atoms. Opens the cited page.Group abbreviationsPh, Boc, OMe, and other groups expand into atoms.moldraw.com
- Yes, according to the manual: Atom editing sets elements, isotopes, charges, and labels. Opens the cited page.Charges, isotopes and atom labelsAtom editing sets elements, isotopes, charges, and labels.moldraw.com
- Yes, according to the manual: Atom-attached lone pairs and radical dots. Opens the cited page.Radicals and lone pairsAtom-attached lone pairs and radical dots.moldraw.com
- Yes, according to the manual: Hover keys change bond order, stereo, atom labels, and charges. Opens the cited page.Keyboard drawingHover keys change bond order, stereo, atom labels, and charges.moldraw.com
- Yes, according to the manual: Lasso selection, rotation handles, flips, and resizing. Opens the cited page.Lasso select and transformsLasso selection, rotation handles, flips, and resizing.moldraw.com
- Yes, according to the manual: Structure Perspective rotates a 3D pose on the drawing canvas. Opens the cited page.Tilt drawings in perspectiveStructure Perspective rotates a 3D pose on the drawing canvas.moldraw.com
Reactions and mechanisms
- Yes, tested by running it: Drew straight and equilibrium arrows. Opens the screenshot.Reaction arrowsDrew straight and equilibrium arrows.moldraw.com
- Yes, tested by running it: Drew electron-flow and fishhook curves. Opens the screenshot.Curved mechanism arrowsDrew electron-flow and fishhook curves.moldraw.com
- Yes, according to the manual: Reaction SMILES input and RXN export preserve reaction chemistry. Opens the cited page.Machine-readable reactionsReaction SMILES input and RXN export preserve reaction chemistry.moldraw.com
- Yes, according to the manual: Automap assigns matching atom numbers across reactants and products. Opens the cited page.Atom mappingAutomap assigns matching atom numbers across reactants and products.moldraw.com
- Yes, according to the manual: Rotatable s, p, d, and hybrid orbital objects. Opens the cited page.Orbitals and symbolsRotatable s, p, d, and hybrid orbital objects.moldraw.com
Figures and layout
- Not established: Canvas text documented; complete rich formatting unverified.Rich text captionsCanvas text documented; complete rich formatting unverified.
- Yes, according to the manual: Drawing tools include shapes, freehand pencil, and brackets. Opens the cited page.Shapes, brackets and curvesDrawing tools include shapes, freehand pencil, and brackets.moldraw.com
- Yes, according to the manual: Align edges or centers; distribute horizontally or vertically. Opens the cited page.Align and distributeAlign edges or centers; distribute horizontally or vertically.moldraw.com
- Yes, according to the manual: Group and Ungroup combine molecules for movement. Opens the cited page.Group and ungroupGroup and Ungroup combine molecules for movement.moldraw.com
- Yes, according to the manual: Cleanup evens bond lengths, angles, and ring shapes. Opens the cited page.2D structure cleanupCleanup evens bond lengths, angles, and ring shapes.moldraw.com
- Yes, according to the manual: ACS, RSC, Nature Portfolio, and Nature Chemistry presets. Opens the cited page.Journal drawing stylesACS, RSC, Nature Portfolio, and Nature Chemistry presets.moldraw.com
- Yes, according to the manual: Settings can save style presets for reuse. Opens the cited page.Reusable custom stylesSettings can save style presets for reuse.moldraw.com
- Yes, according to the manual: Color selected atoms or other drawing content. Opens the cited page.Color controlColor selected atoms or other drawing content.moldraw.com
- Yes, according to the manual: MolScript supports atom and bond highlighter fills. Opens the cited page.Color highlightingMolScript supports atom and bond highlighter fills.moldraw.com
- Yes, seen in the app: Page setup and separate slide list visible. Opens the cited page.Page layout and multipagePage setup and separate slide list visible.
- Yes, according to the manual: Place PNG, JPEG, WebP, GIF, and SVG images. Opens the cited page.Imported picturesPlace PNG, JPEG, WebP, GIF, and SVG images.moldraw.com
- Yes, according to the manual: Separate TLC tool edits lanes, spots, solvent front, and labels. Opens the cited page.TLC plates and tablesSeparate TLC tool edits lanes, spots, solvent front, and labels.moldraw.com
Chemistry intelligence
- Yes, according to the manual: Flags excessive valence, unusual charge, and stereo problems. Opens the cited page.Structure checkingFlags excessive valence, unusual charge, and stereo problems.moldraw.com
- Yes, according to the manual: Computed CIP labels include R, S, E, and Z. Opens the cited page.R/S and E/Z labelsComputed CIP labels include R, S, E, and Z.moldraw.com
- Yes, tested by running it: Caffeine: C8H10N4O2 and 194.19 g/mol. Opens the screenshot.Formula and massCaffeine: C8H10N4O2 and 194.19 g/mol.moldraw.com
- Yes, tested by running it: Paclitaxel details displayed logP 3.736. Opens the screenshot.Property estimatesPaclitaxel details displayed logP 3.736.moldraw.com
- Yes, tested by running it: PubChem search for caffeine placed a structure. Opens the cited page.Name to structurePubChem search for caffeine placed a structure.moldraw.com
- Yes, tested by running it: Caffeine details displayed 1,3,7-trimethylpurine-2,6-dione. Opens the screenshot.Structure to nameCaffeine details displayed 1,3,7-trimethylpurine-2,6-dione.moldraw.com
- Yes, according to the manual: Free-account NMR plugin predicts 1H and 13C shifts. Opens the cited page.NMR predictionFree account. Free-account NMR plugin predicts 1H and 13C shifts.moldraw.com
- Yes, according to the manual: Supports R, R1, and R2 atom labels. Opens the cited page.R-groups and query structuresSupports R, R1, and R2 atom labels.moldraw.com
- Yes, according to the manual: Repeat-unit brackets attach to selected atoms; n/m labels editable. Opens the cited page.Polymers and repeat unitsRepeat-unit brackets attach to selected atoms; n/m labels editable.moldraw.com
- Yes, according to the manual: Companion sequence tool builds peptide, DNA, and RNA structures. Opens the cited page.Peptides and nucleic acidsCompanion sequence tool builds peptide, DNA, and RNA structures.moldraw.com
- Yes, according to the manual: Pro only; image recognition includes 300 scans per month. Opens the cited page.Image to structurePro. Pro only; image recognition includes 300 scans per month.moldraw.com
- Yes, tested by running it: Caffeine PubChem search placed a structure. Opens the cited page.Online structure lookupCaffeine PubChem search placed a structure.moldraw.com
- Partly: Rotates, but cholesterol bonds appeared severely elongated in headless Chromium. Opens the screenshot.3D model viewRotates, but cholesterol bonds appeared severely elongated in headless Chromium.moldraw.com
- Yes, according to the manual: Free-account Crystal View plugin opens CIF and editable crystal drawings. Opens the cited page.Crystal structuresFree account. Free-account Crystal View plugin opens CIF and editable crystal drawings.moldraw.com
Files and exchange
- Partly: CDXML download prompted for an account; import unverified. Opens the screenshot.CDXML import and exportCDXML download prompted for an account; import unverified.moldraw.com
- Yes, according to the manual: Binary CDX import and export. Opens the cited page.CDX import and exportBinary CDX import and export.moldraw.com
- Partly: MOL and SDF opened; MOL download requires account. Opens the screenshot.MOL and SDFMOL and SDF opened; MOL download requires account.moldraw.com
- Partly: Import works; complex output changes stereochemistry; copying requires account. Opens the screenshot.SMILESImport works; complex output changes stereochemistry; copying requires account.moldraw.com
- Yes, tested by running it: Caffeine details displayed an InChI. Opens the screenshot.InChICaffeine details displayed an InChI.moldraw.com
- Yes, according to the manual: MDL RXN reaction export. Opens the cited page.RXN filesMDL RXN reaction export.moldraw.com
- Partly: SVG download prompted for an account. Opens the screenshot.SVG exportFree account. SVG download prompted for an account.moldraw.com
- Partly: PDF download prompted for an account. Opens the screenshot.PDF exportPDF download prompted for an account.
- Partly: PNG download prompted for an account; resolution unverified. Opens the cited page.High-resolution PNGFree account. PNG download prompted for an account; resolution unverified.moldraw.com
- Not established: ChemDraw clipboard roundtrip unverified; file exchange is documented.Paste to and from ChemDrawChemDraw clipboard roundtrip unverified; file exchange is documented.
- Partly: Reopen exported pictures in MolDraw; Office add-ins unavailable. Opens the cited page.Editable in Word or PowerPointReopen exported pictures in MolDraw; Office add-ins unavailable.moldraw.com
- No: PNG/SVG pictures preserve drawing metadata; editing requires manual reopening and replacement. Opens the cited page.Windows Office OLEPNG/SVG pictures preserve drawing metadata; editing requires manual reopening and replacement.moldraw.com
APIs and automation
- Not establishedPython API
- Not establishedJavaScript or TypeScript API
- Partly: MolScript CLI complete; public package publication pending. Opens the cited page.Command-line toolMolScript CLI complete; public package publication pending.moldraw.com
- Yes, according to the manual: Hosted MCP creates, edits, converts, and exports; free account required. Opens the cited page.AI agent controlFree account. Hosted MCP creates, edits, converts, and exports; free account required.moldraw.com
- Yes, according to the manual: Pro only; assistant draws and edits using a monthly allowance. Opens the cited page.Built-in AI assistantPro. Pro only; assistant draws and edits using a monthly allowance.moldraw.com
Embedding and extension
- Yes, according to the manual: Installable plugins; most require a free account. Opens the cited page.PluginsFree account. Installable plugins; most require a free account.moldraw.com
- Yes, according to the manual: Embed https://www.moldraw.com/embed in an iframe; no account required. Opens the cited page.Embed in your own appEmbed https://www.moldraw.com/embed in an iframe; no account required.moldraw.com