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ChemStitch
A browser-based chemical drawing editor for publication figures, property calculations, and AI-assisted structure and reaction analysis.
Free with paid plans. 20 of 65 checklist features confirmed.
Main canvas
Needs an account or a purchase
Needs an account or a purchase
Default drawings
We could not finish testing this tool: The editor redirected to an email sign-in page; an account is required.
Needs an account or a purchase
Caffeine
Needs an account or a purchase
Paclitaxel
Needs an account or a purchase
Cholesterol in 3D
- The sign-in page offers an email link and a 14-day trial.
- No version was displayed on the sign-in page.
Facts
- Runs on
- Browser
- License
- Proprietary hosted service with free drawing and computations; AI uses subscription or student plans.
- Price
- Free drawing; AI US$19/month or US$190/year; verified students free (2026-11-05).
- Plans
- Free Tools: $0; standalone utilities, no sign-up (2026-11-06); Free: $0; drawing and computations (2026-11-06); Student: $0; verified students (2026-11-06); Standard: US$19/month or $190/year; academic $9/month (2026-11-06)
- Relies on
- Ketcher, RDKit, OPSIN. Ketcher canvas; vendor documents RDKit computations and an OPSIN backend.
- Chemistry from
- RDKit
- Interface
- Ketcher structure editor
- Main language
- TypeScript
- Other languages
- Python: Remote FastAPI chemistry backend; C++: RDKit chemistry backend; JavaScript: Raphaël SVG graphics
- Renderer
- Borrowed: Ketcher SVG/Raphaël renderer
- Third-party licenses
- Not established
- Main editor requires an account, internet access, and a desktop browser.
- CDXML is import-only; binary CDX import is unsupported.
- Pricing lists fewer export formats than the file-format manual.
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, according to the manual. Opens the cited page.Single, double and triple bondsFree. chemstitch.ai
- Not establishedWedge, hash and wavy bonds
- Not establishedDative, hydrogen and quadruple bonds
- Not establishedChoose double-bond side
- Yes, according to the manual: Ring templates include benzene; rings can be fused. Opens the cited page.Ring toolsFree. Ring templates include benzene; rings can be fused.chemstitch.ai
- Not establishedChair and Haworth rings
- Not establishedChain tool
- Yes, according to the manual: Functional groups and common molecules, including aspirin and caffeine. Opens the cited page.Template libraryFree. Functional groups and common molecules, including aspirin and caffeine.chemstitch.ai
- Not establishedSave your own templates
- Not establishedGroup abbreviations
- Not establishedCharges, isotopes and atom labels
- Not establishedRadicals and lone pairs
- Not establishedKeyboard drawing
- Not establishedLasso select and transforms
- Not establishedTilt drawings in perspective
Reactions and mechanisms
- Not establishedReaction arrows
- Not establishedCurved mechanism arrows
- Yes, according to the manual: RXN stores explicit reactant and product assignments. Opens the cited page.Machine-readable reactionsFree. RXN stores explicit reactant and product assignments.chemstitch.ai
- Not establishedAtom mapping
- Not establishedOrbitals and symbols
Figures and layout
- Not establishedRich text captions
- Not establishedShapes, brackets and curves
- Not establishedAlign and distribute
- Not establishedGroup and ungroup
- Yes, according to the manual: Clean command adjusts angles, spacing, and ring geometry. Opens the cited page.2D structure cleanupClean command adjusts angles, spacing, and ring geometry.chemstitch.ai
- Yes, according to the manual: ACS Document 1996 preset. Opens the cited page.Journal drawing stylesFree. ACS Document 1996 preset.chemstitch.ai
- Not establishedReusable custom styles
- Not establishedColor control
- Not establishedColor highlighting
- Not establishedPage layout and multipage
- Not establishedImported pictures
- Not establishedTLC plates and tables
Chemistry intelligence
- Yes, according to the manual: Invalid atom labels and valence errors are flagged. Opens the cited page.Structure checkingFree. Invalid atom labels and valence errors are flagged.chemstitch.ai
- Not establishedR/S and E/Z labels
- Not establishedFormula and mass
- Yes, according to the manual: RDKit computes logP and TPSA; calculations remain free. Opens the cited page.Property estimatesRDKit computes logP and TPSA; calculations remain free.chemstitch.ai
- Yes, according to the manual: Requires Standard or verified Student after trial. Opens the cited page.Name to structureStudent. Requires Standard or verified Student after trial.chemstitch.ai
- Yes, according to the manual: Requires Standard or verified Student after trial. Opens the cited page.Structure to nameStudent. Requires Standard or verified Student after trial.chemstitch.ai
- No: No NMR spectrum simulation. Opens the cited page.NMR predictionNo NMR spectrum simulation.chemstitch.ai
- Not establishedR-groups and query structures
- Not establishedPolymers and repeat units
- Not establishedPeptides and nucleic acids
- Yes, according to the manual: AI extraction; requires Standard or verified Student after trial. Opens the cited page.Image to structureStudent. AI extraction; requires Standard or verified Student after trial.chemstitch.ai
- Yes, according to the manual: PubChem via AI; Standard or verified Student after trial. Opens the cited page.Online structure lookupStudent. PubChem via AI; Standard or verified Student after trial.chemstitch.ai
- No: Explicitly limited to 2D drawing and analysis. Opens the cited page.3D model viewExplicitly limited to 2D drawing and analysis.chemstitch.ai
- Not establishedCrystal structures
Files and exchange
- Partly: Import only; CDXML export is explicitly unsupported. Opens the cited page.CDXML import and exportFree. Import only; CDXML export is explicitly unsupported.chemstitch.ai
- No: Binary CDX import unsupported; export remains on roadmap. Opens the cited page.CDX import and exportBinary CDX import unsupported; export remains on roadmap.chemstitch.ai
- Yes, according to the manual: MOL V2000/V3000 and SDF import/export documented; pricing lists fewer formats. Opens the cited page.MOL and SDFMOL V2000/V3000 and SDF import/export documented; pricing lists fewer formats.chemstitch.ai
- Yes, according to the manual: SMILES import and clipboard export. Opens the cited page.SMILESSMILES import and clipboard export.chemstitch.ai
- Yes, according to the manual: InChI import and clipboard export. Opens the cited page.InChIInChI import and clipboard export.chemstitch.ai
- Yes, according to the manual: MDL RXN import and export in reaction mode. Opens the cited page.RXN filesFree. MDL RXN import and export in reaction mode.chemstitch.ai
- Yes, according to the manual: Resolution-independent vector SVG. Opens the cited page.SVG exportResolution-independent vector SVG.chemstitch.ai
- Not establishedPDF export
- Yes, according to the manual: 300, 450, or 600 DPI. Opens the cited page.High-resolution PNGFree. 300, 450, or 600 DPI.chemstitch.ai
- 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
- Not establishedAI agent control
- Yes, according to the manual: Generates structures; Standard or verified Student after trial. Opens the cited page.Built-in AI assistantStudent. Generates structures; Standard or verified Student after trial.chemstitch.ai
Embedding and extension
- Not establishedPlugins
- No: Hosted app blocks framing; no supported editor embedding package documented. Opens the cited page.Embed in your own appHosted app blocks framing; no supported editor embedding package documented.app.chemstitch.ai