This website is biased toward ReShiki, because its maintainer also maintains ReShiki. Please be careful.
MolSketch
A free browser editor for drawing chemical structures and reaction schemes and exporting figures.
Free. 24 of 65 checklist features confirmed.
Official demo
Main canvas
No dark mode
SMILES import changes stereochemistry; default layout has overlaps.
Default drawings
Caffeine
Paclitaxel
No 3D view
Cholesterol in 3D
- Caffeine imported as a black drawing with bold atom labels.
- Paclitaxel's default layout has overlapping bonds and labels.
- Paclitaxel SMILES retained connectivity but changed or lost ten stereocenters.
- The default caffeine PNG measured 350 by 335 pixels.
- No version number was visible in the editor.
Facts
- Version we tested
- build m0PiI1PnCmq4Tn2qz-p-a
- Runs on
- Browser, iOS, Android
- License
- Free hosted service under MolSketch's terms; no open-source license stated.
- Price
- Free (2026-11-05)
- Relies on
- RDKit, DECIMER. Canvas provenance unconfirmed; vendor credits RDKit for chemistry and DECIMER for image recognition.
- Draws with
- Custom HTML Canvas 2D renderer; custom SVG serialization and native PowerPoint shapes/text.
- Chemistry from
- RDKit/RDKit.js for validation and SMILES processing; SmilesDrawer for SMILES layout.
- Interface
- React / Next.js
- Main language
- JavaScript
- Other languages
- C++: RDKit WebAssembly chemistry; Python: DECIMER image recognition service
- Renderer
- Original: In-house Canvas 2D atom/bond renderer
- Third-party licenses
- RDKit BSD-3-Clause; DECIMER package MIT with separate model terms; KaTeX fonts OFL-1.1. The separate PDF translation tool uses pikepdf MPL-2.0.
- Offline support is not documented; the offered editor is browser-hosted.
- Logged-out OCR and handwriting recognition are limited to three uses daily.
- OCR and structure generation may send inputs to servers or external services.
In use
Screenshots from our test of this version.
Single, double and triple bonds
A triple bond drawn on the editor canvas.
Wedge, hash and wavy bonds
Solid and hashed wedge bonds on the canvas.
Ring tools
A benzene ring and ring tools in the editor.
Template library
The amino acid template library, including glycine and alanine.
Charges, isotopes and atom labels
A caffeine structure with nitrogen and oxygen atom labels.
Lasso select and transforms
A selected curved arrow with a rotation handle and controls.
Reaction arrows
A forward arrow and the reaction arrow menu.
Curved mechanism arrows
A selected curved arrow with visible control points.
Image to structure
The Auto Generate panel offers OCR image upload.
SMILES
A caffeine drawing with its SMILES output.
SVG export
The download menu offers SVG export for the drawing.
High-resolution PNG
The download menu offers PNG export for the drawing.
Editable in Word or PowerPoint
The download menu offers a PowerPoint file.
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: Clicked one bond through single, double, and triple orders. Opens the screenshot.Single, double and triple bondsClicked one bond through single, double, and triple orders.molsketch.net
- Partly: Solid and hashed wedges drawn; no wavy tool found. Opens the screenshot.Wedge, hash and wavy bondsSolid and hashed wedges drawn; no wavy tool found.molsketch.net
- Not establishedDative, hydrogen and quadruple bonds
- Not establishedChoose double-bond side
- Yes, tested by running it: Drew benzene; cyclopentane and cyclohexane tools visible. Opens the screenshot.Ring toolsDrew benzene; cyclopentane and cyclohexane tools visible.molsketch.net
- Not establishedChair and Haworth rings
- Yes, according to the manual: Dragging sets zigzag chain length. Opens the cited page.Chain toolDragging sets zigzag chain length.molsketch.net
- Yes, tested by running it: Placed glycine from amino acid templates. Opens the screenshot.Template libraryPlaced glycine from amino acid templates.molsketch.net
- Not establishedSave your own templates
- Not establishedGroup abbreviations
- Partly: Charges/custom labels supported; stored isotopes lack editor/display controls. Opens the cited page.Charges, isotopes and atom labelsCharges/custom labels supported; stored isotopes lack editor/display controls.molsketch.net
- Not establishedRadicals and lone pairs
- Not establishedKeyboard drawing
- Partly: Lasso, rotation, and flips; no whole-selection resizing control. Opens the cited page.Lasso select and transformsLasso, rotation, and flips; no whole-selection resizing control.molsketch.net
- 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.molsketch.net
- Yes, tested by running it: Drew curved arrow; selection exposes control points. Opens the screenshot.Curved mechanism arrowsDrew curved arrow; selection exposes control points.molsketch.net
- Not establishedMachine-readable reactions
- Not establishedAtom mapping
- Not establishedOrbitals and symbols
Figures and layout
- Yes, according to the manual: Font size, bold, italic, underline, superscript, and subscript. Opens the cited page.Rich text captionsFont size, bold, italic, underline, superscript, and subscript.molsketch.net
- Not establishedShapes, brackets and curves
- Not establishedAlign and distribute
- Yes, according to the manual: Group/ungroup atoms, bonds, arrows, and text; move selections together. Opens the cited page.Group and ungroupGroup/ungroup atoms, bonds, arrows, and text; move selections together.molsketch.net
- Yes, according to the manual: Clean Structure adjusts coordinates, bond geometry, arrows, and text. Opens the cited page.2D structure cleanupClean Structure adjusts coordinates, bond geometry, arrows, and text.molsketch.net
- Not establishedJournal drawing styles
- Not establishedReusable custom styles
- Yes, according to the manual: Individual atom colors, bond colors, and endpoint gradients. Opens the cited page.Color controlIndividual atom colors, bond colors, and endpoint gradients.molsketch.net
- Partly: Selection/hover halos exist; SVG and PNG exports omit them. Opens the cited page.Color highlightingSelection/hover halos exist; SVG and PNG exports omit them.molsketch.net
- Not establishedPage layout and multipage
- Not establishedImported pictures
- Not establishedTLC plates and tables
Chemistry intelligence
- Yes, according to the manual: Checks valence, invalid elements, duplicate bonds, and RDKit validity. Opens the cited page.Structure checkingChecks valence, invalid elements, duplicate bonds, and RDKit validity.molsketch.net
- Not establishedR/S and E/Z labels
- No: No formula or mass command found for editor drawing. Opens the cited page.Formula and massNo formula or mass command found for editor drawing.
- Yes, according to the manual: Separate SMILES analyzer computes Crippen logP and TPSA. Opens the cited page.Property estimatesSeparate SMILES analyzer computes Crippen logP and TPSA.molsketch.net
- Yes, tested by running it: Benzene produced a preview and loaded onto canvas. Opens the cited page.Name to structureBenzene produced a preview and loaded onto canvas.molsketch.net
- No: No structure-to-name command found in editor. Opens the cited page.Structure to nameNo structure-to-name command found in editor.
- Not establishedNMR prediction
- Not establishedR-groups and query structures
- Yes, according to the manual: Dedicated repeat-unit objects link structural groups and repeat labels. Opens the cited page.Polymers and repeat unitsDedicated repeat-unit objects link structural groups and repeat labels.molsketch.net
- Not establishedPeptides and nucleic acids
- Yes, according to the manual: OCR imports printed or handwritten structures as editable chemistry. Opens the cited page.Image to structureOCR imports printed or handwritten structures as editable chemistry.molsketch.net
- Yes, according to the manual: Name and CAS lookup through PubChem PUG REST. Opens the cited page.Online structure lookupName and CAS lookup through PubChem PUG REST.molsketch.net
- No: No 3D view found in editor or chemistry navigation. Opens the cited page.3D model viewNo 3D view found in editor or chemistry navigation.
- Not establishedCrystal structures
Files and exchange
- No: No CDXML import or export control found. Opens the cited page.CDXML import and exportNo CDXML import or export control found.
- Not establishedCDX import and export
- No: No MOL or SDF import or export control found. Opens the cited page.MOL and SDFNo MOL or SDF import or export control found.
- Partly: Caffeine matched; paclitaxel output changed ten stereocenters. Opens the screenshot.SMILESCaffeine matched; paclitaxel output changed ten stereocenters.molsketch.net
- Not establishedInChI
- Not establishedRXN files
- Yes, tested by running it: Downloaded SVG for both structures. Opens the screenshot.SVG exportDownloaded SVG for both structures.molsketch.net
- No: Download menu offers PNG, SVG and PowerPoint only. Opens the cited page.PDF exportDownload menu offers PNG, SVG and PowerPoint only.
- Partly: PNG exported; default caffeine image reports 72 dpi. Opens the screenshot.High-resolution PNGPNG exported; default caffeine image reports 72 dpi.
- Not establishedPaste to and from ChemDraw
- Yes, according to the manual: PowerPoint objects remain editable as text and shapes. Opens the cited page.Editable in Word or PowerPointPowerPoint objects remain editable as text and shapes.molsketch.net
- No: PPTX export creates editable PowerPoint text and shapes, not OLE objects. Opens the cited page.Windows Office OLEPPTX export creates editable PowerPoint text and shapes, not OLE objects.molsketch.net
APIs and automation
- Not establishedPython API
- Not establishedJavaScript or TypeScript API
- Not establishedCommand-line tool
- Not establishedAI agent control
- Not establishedBuilt-in AI assistant
Embedding and extension
- Not establishedPlugins
- No: No supported embedding route found; hosted editor blocks external iframes. Opens the cited page.Embed in your own appNo supported embedding route found; hosted editor blocks external iframes.molsketch.net