Replacing Marvin JS, or a Marvin academic license
Marvin JS can no longer be bought after December 31, 2026, and it reaches end of life on December 31, 2027. The free individual academic Marvin licenses ended on July 31, 2026.
Athanor is a free chemistry editor for the browser, and its editor can be embedded in your own page, a course or a compound database, with a small script that does what most Marvin JS pages use it for.
Windows 10 and 11 Updates itself from the Store
Runs in your browser. No account needed to draw.
An embeddable editor
Set a structure, read it back as SMILES, a molfile, SVG or PNG, hear when it changes, and switch it to view only, through a documented postMessage protocol or an <athanor-editor> element.
Free for the people drawing
Students and researchers use Athanor for free, with no academic email or license request.
Files in and out
MOL V2000 and V3000, SDF, RXN, SMILES, and ChemDraw’s CDX and CDXML.
Teaching built in
Problem sets with 21 question types, automatic grading by rules, and export to Moodle XML and QTI 2.1.
What Marvin does that Athanor does not
Marvin predicts NMR spectra and has a long list of calculator plugins. Athanor’s embed is version 1: it covers structures, not reactions with mapping. Write to [email protected] before you plan a migration, and we will tell you plainly whether it fits.
Athanor, Marvin and the others, row by row
Swipe the table to see every tool
 Athanor | ChemDraw | ChemDoodle | Marvin | Octet Draw | Discontinued Aug 2026ChemSketch | |
|---|---|---|---|---|---|---|
| Price & access | ||||||
| Price | Free | Prime $700/yrProfessional $1,355/yr | $199/yror $999 lifetime | $29/mo academic$99/mo commercial | Free | No longer sold |
| Free for commercial work | – | – | – | – | ||
| Full editor in the browser | Enterprise plan | Developer toolkit | – | – | ||
| Prediction | ||||||
| Products predicted as you draw | – | From arrow pushing | – | – | – | |
| Retrosynthesis route planning | – | Manual disconnections | – | – | – | |
| Property prediction | Basic | |||||
| AI assistant that draws and animates | – | – | – | – | – | |
| Teaching | ||||||
| Problem sets with automatic grading | 21 question types | – | – | – | – | – |
| Mechanism checking | – | – | – | – | – | |
| Moodle XML and QTI export | – | – | – | – | – | |
| Drawing & visualization | ||||||
| 2D structure drawing | ||||||
| 3D models | – | |||||
| Orbitals and MO diagrams | Orbital palette | – | – | – | ||
| Animated mechanisms | – | – | – | – | – | |
| Biopolymers (HELM, peptides, DNA) | – | – | – | – | ||
| Data & workflow | ||||||
| Compound library with cited safety data | PubChem add‑in | – | – | – | – | |
| Live collaboration | In testing | Enterprise plan | – | – | – | – |
| Opens ChemDraw files | ||||||
| Name to structure for any IUPAC name | Online | Offline | – | |||
| Platforms | ||||||
| Desktop app | Windows | Windows, Mac | Windows, Mac, Linux | Windows, Mac, Linux | Windows | |
| Mac and Linux | In the browser | Mac | – | |||
| Works offline | Desktop app | Desktop | ||||
| Open source | – | – | – | – | Apache‑2.0 | – |
| Where others do more | ||||||
| ¹H and ¹³C NMR prediction | Predicted, AI | – | ||||
| Fully offline, no account | – | – | ||||
| Office and ELN integration | – | LabArchives | Office, on Mac | – |
Prices as of October 2026, from each vendor’s own page. Check with the vendor before you buy.
Sources