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FreeChemDraw
A free browser workspace for drawing chemical structures and reactions, converting names, calculating properties, and exporting figures.
Free. 46 of 65 checklist features confirmed.
Official demo
Main canvas
Default drawings
Caffeine
Paclitaxel
Cholesterol in 3D
- About identifies embedded Ketcher 3.18.0; no FreeChemDraw release version shown.
- Default caffeine layout uses aromatic circles and colored heteroatoms.
- Default cholesterol 3D view shows a ball-and-stick model.
- Default PNG carried 72 dpi metadata; editor offers high and low resolution.
- Name conversion rejected aspirin but accepted its systematic name.
- Current Kekulé caffeine SMILES produced alternating double bonds in the default layout.
Facts
- Version we tested
- 3.18.0
- Runs on
- Browser
- License
- Free hosted service under proprietary site terms; generated drawings may be used commercially.
- Price
- Free
- Relies on
- Ketcher, Indigo, 3Dmol.js. Embeds Ketcher 3.18; Indigo handles chemistry and 3Dmol.js displays 3D structures.
- Draws with
- Ketcher SVG/Raphael editor; Indigo image rendering
- Chemistry from
- Indigo (embedded Ketcher editor)
- Interface
- React (embedded Ketcher 3.18.0)
- Main language
- TypeScript
- Other languages
- JavaScript: Workspace and 3Dmol.js viewer; C++: Indigo WebAssembly chemistry and image rendering; C: InChI via Indigo WebAssembly
- Renderer
- Borrowed: Ketcher SVG/Raphaël; Indigo generated images
- Third-party licenses
- Server-side OSRA has GPL-2.0-or-later components; Font Awesome icons/fonts use CC-BY-4.0/OFL-1.1. Ketcher upstream NOTICE also lists LGPL-2.1, MPL-1.0 and AFL-3.0 dependencies without component mapping.
- Properties, recognition, naming and 3D generation require server processing.
- Browser autosave is retained for only 10 minutes.
- The ACS preset does not guarantee compliance with journal requirements.
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
Solid wedge, hashed wedge and wavy bonds on the canvas.
Ring tools
Benzene and cyclohexane rings on the drawing canvas.
Template library
Structure library showing template categories and amino acid structures.
Save your own templates
Save Structure dialog with a Save to Templates button.
Reaction arrows
Forward and equilibrium arrows on the drawing canvas.
Curved mechanism arrows
Curved arrow on the drawing canvas.
Machine-readable reactions
Save Structure dialog with MDL Rxnfile V2000 selected.
Shapes, brackets and curves
Shape tool menu with ellipse, rectangle and line icons.
Journal drawing styles
Benzoic acid drawing with Default and ACS style options.
Structure checking
Settings dialog with Show valence warnings enabled.
Formula and mass
Calculated molecular formula, molecular weight and exact mass.
Property estimates
Calculated TPSA and LogP in the molecular properties results.
Name to structure
Ethanol name and resulting structure in the editor.
Structure to name
Ethanol structure and generated IUPAC name.
Image to structure
Image Recognition panel with upload and Recognize controls.
Online structure lookup
Structure Lookup search field beside the editor.
3D model view
Cholesterol ball-and-stick model with 3D view controls.
CDXML import and export
Open structure dialog containing CDXML text.
CDX import and export
Local file upload lists CDX among supported formats.
MOL and SDF
Save Structure dialog showing an MDL Molfile preview.
SMILES
Benzoic acid structure and its displayed SMILES.
RXN files
Save Structure dialog with MDL Rxnfile V2000 selected.
SVG export
Benzoic acid drawing with an Export as SVG button.
High-resolution PNG
Benzoic acid drawing with an Export as PNG button.
AI agent control
FreeChemDraw MCP card and Explore MCP Tools link.
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 separate single, double, and triple bonds. Opens the screenshot.Single, double and triple bondsDrew separate single, double, and triple bonds.github.com
- Yes, tested by running it: Drew solid wedge, hashed wedge, and wavy bonds. Opens the screenshot.Wedge, hash and wavy bondsDrew solid wedge, hashed wedge, and wavy bonds.github.com
- Yes, according to the manual: Dative and hydrogen bond tools. Opens the cited page.Dative, hydrogen and quadruple bondsDative and hydrogen bond tools.github.com
- Not establishedChoose double-bond side
- Yes, tested by running it: Placed benzene and cyclohexane with ring tools. Opens the screenshot.Ring toolsPlaced benzene and cyclohexane with ring tools.github.com
- Yes, according to the manual: Built-in chair and boat templates. Opens the cited page.Chair and Haworth ringsBuilt-in chair and boat templates.github.com
- Yes, according to the manual: Dragging determines chain length. Opens the cited page.Chain toolDragging determines chain length.github.com
- Yes, tested by running it: Selected and placed D-alanine from structure library. Opens the screenshot.Template librarySelected and placed D-alanine from structure library.github.com
- Yes, according to the manual: Save to Templates creates reusable user templates. Opens the cited page.Save your own templatesSave to Templates creates reusable user templates.github.com
- Yes, according to the manual: Functional groups expand, contract and retain underlying chemistry. Opens the cited page.Group abbreviationsFunctional groups expand, contract and retain underlying chemistry.github.com
- Yes, according to the manual: Editable charge, isotope, element, pseudoatom and alias fields. Opens the cited page.Charges, isotopes and atom labelsEditable charge, isotope, element, pseudoatom and alias fields.github.com
- Yes, according to the manual: Monoradical and singlet/triplet diradical atom properties. Opens the cited page.Radicals and lone pairsMonoradical and singlet/triplet diradical atom properties.github.com
- Yes, according to the manual: Hotkeys alter hovered atoms, charges and atom properties. Opens the cited page.Keyboard drawingHotkeys alter hovered atoms, charges and atom properties.github.com
- Partly: Lasso, rotate and flip; resizing limited to graphical objects. Opens the cited page.Lasso select and transformsLasso, rotate and flip; resizing limited to graphical objects.github.com
- Not establishedTilt drawings in perspective
Reactions and mechanisms
- Yes, tested by running it: Drew forward and equilibrium arrows. Opens the screenshot.Reaction arrowsDrew forward and equilibrium arrows.github.com
- Partly: Drew curved full-head arrow; editing was not verified. Opens the screenshot.Curved mechanism arrowsDrew curved full-head arrow; editing was not verified.github.com
- Yes, according to the manual: Embedded Ketcher preserves reactants, products and reagents in reaction formats. Opens the cited page.Machine-readable reactionsEmbedded Ketcher preserves reactants, products and reagents in reaction formats.github.com
- Yes, according to the manual: Embedded Ketcher offers manual mapping, automatic mapping and unmapping. Opens the cited page.Atom mappingEmbedded Ketcher offers manual mapping, automatic mapping and unmapping.github.com
- Not establishedOrbitals and symbols
Figures and layout
- Yes, according to the manual: Editable text supports styling, subscripts and superscripts. Opens the cited page.Rich text captionsEditable text supports styling, subscripts and superscripts.github.com
- Yes, according to the manual: Ellipse, rectangle and line tools; chemical S-group brackets. Opens the cited page.Shapes, brackets and curvesEllipse, rectangle and line tools; chemical S-group brackets.github.com
- Not establishedAlign and distribute
- Not establishedGroup and ungroup
- Yes, according to the manual: Clean Up assigns uniform bond lengths and angles. Opens the cited page.2D structure cleanupClean Up assigns uniform bond lengths and angles.github.com
- Yes, according to the manual: ACS preset applies coordinated bond, font and spacing settings. Opens the cited page.Journal drawing stylesACS preset applies coordinated bond, font and spacing settings.freechemdraw.com
- Yes, according to the manual: Bond and font settings can be saved and reloaded as files. Opens the cited page.Reusable custom stylesBond and font settings can be saved and reloaded as files.github.com
- Yes, according to the manual: Individual atoms and bonds support eight highlighting colors. Opens the cited page.Color controlIndividual atoms and bonds support eight highlighting colors.github.com
- Yes, according to the manual: Embedded Ketcher provides eight-color backgrounds behind atoms and bonds. Opens the cited page.Color highlightingEmbedded Ketcher provides eight-color backgrounds behind atoms and bonds.github.com
- Not establishedPage layout and multipage
- Yes, according to the manual: PNG and SVG images can be placed on the canvas. Opens the cited page.Imported picturesPNG and SVG images can be placed on the canvas.github.com
- Not establishedTLC plates and tables
Chemistry intelligence
- Yes, according to the manual: Embedded Ketcher underlines atoms with incorrect valence in red. Opens the cited page.Structure checkingEmbedded Ketcher underlines atoms with incorrect valence in red.github.com
- Yes, according to the manual: Embedded Ketcher computes R/S, r/s and E/Z descriptors. Opens the cited page.R/S and E/Z labelsEmbedded Ketcher computes R/S, r/s and E/Z descriptors.github.com
- Yes, tested by running it: Ethanol showed C2H6O, 46.069 molecular weight, 46.042 exact mass. Opens the screenshot.Formula and massEthanol showed C2H6O, 46.069 molecular weight, 46.042 exact mass.freechemdraw.com
- Yes, tested by running it: Ethanol showed TPSA 20.23 and LogP -0.001. Opens the screenshot.Property estimatesEthanol showed TPSA 20.23 and LogP -0.001.freechemdraw.com
- Yes, tested by running it: Ethanol and systematic aspirin name worked; aspirin alone failed. Opens the screenshot.Name to structureEthanol and systematic aspirin name worked; aspirin alone failed.freechemdraw.com
- Yes, tested by running it: Ethanol and systematic aspirin structures returned names. Opens the screenshot.Structure to nameEthanol and systematic aspirin structures returned names.freechemdraw.com
- Not establishedNMR prediction
- Yes, according to the manual: Embedded Ketcher supports R-groups, attachment points and R-group logic. Opens the cited page.R-groups and query structuresEmbedded Ketcher supports R-groups, attachment points and R-group logic.github.com
- Yes, according to the manual: Embedded Ketcher supports SRU polymers, connectivity and copolymer subtypes. Opens the cited page.Polymers and repeat unitsEmbedded Ketcher supports SRU polymers, connectivity and copolymer subtypes.github.com
- Yes, according to the manual: Embedded Ketcher supports peptides, nucleic acids, sequences and monomers. Opens the cited page.Peptides and nucleic acidsEmbedded Ketcher supports peptides, nucleic acids, sequences and monomers.github.com
- Yes, according to the manual: Recognition produces an editable structure; server processing required. Opens the cited page.Image to structureRecognition produces an editable structure; server processing required.freechemdraw.com
- Yes, according to the manual: Searches CAS numbers, formulas and English names through ChemTradeHub. Opens the cited page.Online structure lookupSearches CAS numbers, formulas and English names through ChemTradeHub.freechemdraw.com
- Yes, tested by running it: Generated cholesterol model from SMILES and rotated it by dragging. Opens the screenshot.3D model viewGenerated cholesterol model from SMILES and rotated it by dragging.freechemdraw.com
- Not establishedCrystal structures
Files and exchange
- Yes, tested by running it: Exported caffeine CDXML and reopened it in editor. Opens the screenshot.CDXML import and exportExported caffeine CDXML and reopened it in editor.github.com
- Yes, according to the manual: Binary and Base64 CDX through embedded Ketcher in molecule mode. Opens the cited page.CDX import and exportBinary and Base64 CDX through embedded Ketcher in molecule mode.github.com
- Yes, tested by running it: Imported and exported MOL; SDF save option visible. Opens the screenshot.MOL and SDFImported and exported MOL; SDF save option visible.github.com
- Yes, tested by running it: Imported caffeine SMILES and copied generated SMILES. Opens the screenshot.SMILESImported caffeine SMILES and copied generated SMILES.freechemdraw.com
- Yes, according to the manual: Embedded Ketcher supports InChI, AuxInfo and InChIKey. Opens the cited page.InChIEmbedded Ketcher supports InChI, AuxInfo and InChIKey.github.com
- Yes, according to the manual: Embedded Ketcher reads and writes MDL RXN reactions. Opens the cited page.RXN filesEmbedded Ketcher reads and writes MDL RXN reactions.github.com
- Yes, tested by running it: Downloaded SVG drawings for all three structures. Opens the screenshot.SVG exportDownloaded SVG drawings for all three structures.freechemdraw.com
- No: No PDF option in editor save or workspace export controls. Opens the cited page.PDF exportNo PDF option in editor save or workspace export controls.
- Partly: PNG downloaded at 526×194; high-resolution option untested. Opens the screenshot.High-resolution PNGPNG downloaded at 526×194; high-resolution option untested.github.com
- Not establishedPaste to and from ChemDraw
- Not establishedEditable in Word or PowerPoint
- Not establishedWindows Office OLE
APIs and automation
- Not establishedPython API
- Not establishedJavaScript or TypeScript API
- Not establishedCommand-line tool
- Yes, according to the manual: Separate MCP service; editor transfer requires manual SMILES/MOL import. Opens the cited page.AI agent controlSeparate MCP service; editor transfer requires manual SMILES/MOL import.freechemdraw.com
- Not establishedBuilt-in AI assistant
Embedding and extension
- Not establishedPlugins
- No: Hosted editor blocks external iframes; no documented embedding SDK. Opens the cited page.Embed in your own appHosted editor blocks external iframes; no documented embedding SDK.freechemdraw.com