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ChemEdit
Obsidian plugin for drawing chemical structures, editing chemistry files, and maintaining electronic lab notebooks.
Open source. 49 of 65 checklist features confirmed.
Official demo
Main canvas
Dark mode changes interface; drawing canvas remains white.
Default drawings
Caffeine
Paclitaxel
Cholesterol in 3D
- Default editor colors nitrogen blue and oxygen red.
- Paclitaxel layout includes wedge bonds, hashed bonds, and ABS label.
- Cholesterol SMILES stays planar; supplied 3D SDF rotates in Miew.
- MOL/CDXML previews show black bonds on the dark host background.
- Host PDF rasterizes chemistry; white bonds lose contrast on white.
Facts
- GitHub stars
- 3 stars on 6 Nov 2026
- First commit
- 5 Aug 2026
- Repository activity
- 85 commits, 1 contributor, last push 21 Oct 2026
- Latest version
- 1.4.3
- Version we tested
- 1.4.3
- Runs on
- macOS, Windows, Linux
- License
- MIT-licensed Obsidian plugin.
- Price
- Free
- Relies on
- Ketcher, Indigo, OpenChemLib, SmilesDrawer, Miew. Embeds packaged Ketcher; Indigo supplies chemistry, OpenChemLib properties, SmilesDrawer previews, and Miew 3D.
- Draws with
- SVG through Ketcher/Raphael, Indigo exports, and SmilesDrawer; optional HTML canvas previews.
- Chemistry from
- Indigo via Ketcher standalone, and OpenChemLib.
- Interface
- React within Obsidian.
- Main language
- TypeScript
- Other languages
- JavaScript: Raphaël, SmilesDrawer, Miew and runtime; C++: Indigo chemistry and preview WebAssembly; C: InChI support compiled to WebAssembly; Java: OpenChemLib compiled to JavaScript
- Renderer
- Borrowed: Ketcher/Raphaël, SmilesDrawer, and Indigo
- Third-party licenses
- Ketcher's notices list LGPL-2.1 and MPL-1.0 dependencies alongside Apache-2.0, MIT and BSD components.
- Download
- 277 MB
- Installed
- 595 MB
- Requires desktop Obsidian; the manifest excludes iOS and Android.
- Complex ChemDraw formatting and proprietary CDXML objects may not round-trip.
- ChemEdit's SDF save option writes MOL data; use Ketcher's own SDF exporter.
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
Three-membered, six-membered, and aromatic rings above the ring toolbar.
Charges, isotopes and atom labels
Atom Properties dialog with label, alias, charge, and isotope fields.
Radicals and lone pairs
Radical selector in the Atom Properties dialog.
Reaction arrows
Forward and equilibrium arrows on the drawing canvas.
Curved mechanism arrows
Curved arrow with a full arrowhead on the drawing canvas.
Formula and mass
Calculated formula, molecular weight, exact mass, and elemental analysis.
Name to structure
Web name lookup shows caffeine and its resulting structure.
Online structure lookup
Web lookup for caffeine with a structure result.
3D model view
Miew dialog displaying a three-dimensional molecular model.
CDXML import and export
Opened CDXML document displays a caffeine structure.
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 manually. Opens the screenshot.Single, double and triple bondsDrew single, double, and triple bonds manually.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 bonds. Opens the cited page.Dative, hydrogen and quadruple bondsDative and hydrogen bonds.github.com
- Not establishedChoose double-bond side
- Yes, tested by running it: Placed cyclopropane, cyclohexane, and benzene rings. Opens the screenshot.Ring toolsPlaced cyclopropane, cyclohexane, and benzene rings.github.com
- Yes, according to the manual: Includes chair conformations. Opens the cited page.Chair and Haworth ringsIncludes chair conformations.github.com
- Yes, according to the manual. Opens the cited page.Chain toolgithub.com
- Yes, tested by running it: Placed L-alanine from the structure library. Opens the cited page.Template libraryPlaced L-alanine from the structure library.github.com
- Yes, according to the manual. Opens the cited page.Save your own templatesgithub.com
- Yes, according to the manual. Opens the cited page.Group abbreviationsgithub.com
- Yes, according to the manual. Opens the cited page.Charges, isotopes and atom labelsgithub.com
- Yes, according to the manual: Monoradical and diradical dots. Opens the cited page.Radicals and lone pairsMonoradical and diradical dots.github.com
- Yes, tested by running it: Number keys changed bond order during drawing. Opens the cited page.Keyboard drawingNumber keys changed bond order during drawing.github.com
- Partly: Lasso, rotation and flips; resizing limited to images and graphical objects. Opens the cited page.Lasso select and transformsLasso, rotation and flips; resizing limited to images and 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
- Yes, tested by running it: Drew curved arrow and moved its endpoint handle. Opens the screenshot.Curved mechanism arrowsDrew curved arrow and moved its endpoint handle.github.com
- Yes, according to the manual: RXN export and chemically encoded ELN reactants/products. Opens the cited page.Machine-readable reactionsRXN export and chemically encoded ELN reactants/products.github.com
- Yes, according to the manual. Opens the cited page.Atom mappinggithub.com
- Not establishedOrbitals and symbols
Figures and layout
- Yes, according to the manual: Font size, bold, italic, subscripts, and superscripts. Opens the cited page.Rich text captionsFont size, bold, italic, subscripts, and superscripts.github.com
- Yes, according to the manual: Geometric shapes and S-group brackets. Opens the cited page.Shapes, brackets and curvesGeometric shapes and S-group brackets.github.com
- Not establishedAlign and distribute
- Not establishedGroup and ungroup
- Yes, according to the manual. Opens the cited page.2D structure cleanupgithub.com
- Yes, according to the manual: ACS Document 1996 preset. Opens the cited page.Journal drawing stylesACS Document 1996 preset.github.com
- Yes, according to the manual: Bond and font settings save/reload as JSON. Opens the cited page.Reusable custom stylesBond and font settings save/reload as JSON.github.com
- Partly: Individual colored highlights; atom-label and bond-stroke colors remain unchanged. Opens the cited page.Color controlIndividual colored highlights; atom-label and bond-stroke colors remain unchanged.github.com
- Yes, according to the manual: Ketcher provides eight-color background highlights for individual atoms and bonds. Opens the cited page.Color highlightingKetcher provides eight-color background highlights for individual atoms and bonds.github.com
- Not establishedPage layout and multipage
- Yes, according to the manual: PNG and SVG images. Opens the cited page.Imported picturesPNG and SVG images.github.com
- Yes, according to the manual: Editable ELN tables and separate TLC photo annotations. Opens the cited page.TLC plates and tablesEditable ELN tables and separate TLC photo annotations.github.com
Chemistry intelligence
- Yes, according to the manual: Invalid valence is underlined in red. Opens the cited page.Structure checkingInvalid valence is underlined in red.github.com
- Yes, according to the manual. Opens the cited page.R/S and E/Z labelsgithub.com
- Yes, tested by running it: Caffeine: C8H10N4O2, molecular weight 194.194, exact mass 194.080. Opens the screenshot.Formula and massCaffeine: C8H10N4O2, molecular weight 194.194, exact mass 194.080.github.com
- Yes, according to the manual: OpenChemLib computes logP and TPSA. Opens the cited page.Property estimatesOpenChemLib computes logP and TPSA.github.com
- Yes, tested by running it: Web lookup for caffeine returned a structure. Opens the screenshot.Name to structureWeb lookup for caffeine returned a structure.github.com
- Yes, tested by running it: Returned 1,3,7-trimethylpurine-2,6-dione for caffeine. Opens the cited page.Structure to nameReturned 1,3,7-trimethylpurine-2,6-dione for caffeine.github.com
- Partly: Opens external nmrdb 1H prediction; no built-in predictor. Opens the cited page.NMR predictionOpens external nmrdb 1H prediction; no built-in predictor.github.com
- Yes, according to the manual. Opens the cited page.R-groups and query structuresgithub.com
- Yes, according to the manual: SRU and copolymer S-groups. Opens the cited page.Polymers and repeat unitsSRU and copolymer S-groups.github.com
- Yes, according to the manual: Ketcher sequence/macromolecule mode; complex sequences can fall back. Opens the cited page.Peptides and nucleic acidsKetcher sequence/macromolecule mode; complex sequences can fall back.github.com
- No: Image Recognition service unavailable; clicking did nothing. Opens the cited page.Image to structureImage Recognition service unavailable; clicking did nothing.github.com
- Yes, tested by running it: Web chemical-name lookup returned caffeine structure. Opens the screenshot.Online structure lookupWeb chemical-name lookup returned caffeine structure.github.com
- Yes, tested by running it: SDF rotates in Miew; SMILES did not generate depth coordinates. Opens the screenshot.3D model viewSDF rotates in Miew; SMILES did not generate depth coordinates.github.com
- Not establishedCrystal structures
Files and exchange
- Yes, tested by running it: Exported caffeine and reopened CDXML in the editor. Opens the screenshot.CDXML import and exportExported caffeine and reopened CDXML in the editor.github.com
- Yes, according to the manual: Use Ketcher's own file dialogs. Opens the cited page.CDX import and exportUse Ketcher's own file dialogs.github.com
- Yes, tested by running it: MOL export reopened; cholesterol 3D SDF imported successfully. Opens the cited page.MOL and SDFMOL export reopened; cholesterol 3D SDF imported successfully.github.com
- Yes, tested by running it: Imported fixtures and saved generated Daylight SMILES. Opens the cited page.SMILESImported fixtures and saved generated Daylight SMILES.github.com
- Yes, according to the manual. Opens the cited page.InChIgithub.com
- Yes, according to the manual. Opens the cited page.RXN filesgithub.com
- Yes, tested by running it: Saved default SVG exports for all three fixtures. Opens the cited page.SVG exportSaved default SVG exports for all three fixtures.github.com
- Partly: Host PDF rasterizes chemistry; white bonds lose contrast on white. Opens the cited page.PDF exportHost PDF rasterizes chemistry; white bonds lose contrast on white.
- Partly: Default PNG 223×162; high-resolution setting visible but untested. Opens the cited page.High-resolution PNGDefault PNG 223×162; high-resolution setting visible but 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
- Yes, according to the manual: Public typed editor, rendering and conversion API. Opens the cited page.JavaScript or TypeScript APIPublic typed editor, rendering and conversion API.raw.githubusercontent.com
- Not establishedCommand-line tool
- Not establishedAI agent control
- Not establishedBuilt-in AI assistant
Embedding and extension
- Not establishedPlugins
- Yes, according to the manual: Install Obsidian plugin; open its integrated Ketcher drawing modal. Opens the cited page.Embed in your own appInstall Obsidian plugin; open its integrated Ketcher drawing modal.github.com