ChemWidget |ChemWidget is a chemical structure editor and viewer for the web. Built with pure HTML5 and Javascript, ChemWidget runs in any modern web browser.

  • ChemWidget has been designed from the ground up to be touch-ready.

    Most important UI elements are generously sized, making it easy to manipulate the structures on a touch screen.


  • Four times the pixels. Beautiful icons. Crystal-clear structures.

    ChemWidget is aware of Retina-class displays, and turns on pixel-doubling automatically on suitable devices.



Designed by Chemists, for Chemists

The language of chemistry is inherently graphical. This makes the task of communicating chemistry using text-based websites uniquely challenging. Traditionally, server-side generated images, browser plugins (such as Chime) and custom Java applets have been used to display and input chemical structures. However, the emergence of modern mobile devices, such as tablets and smartphones, the increasingly dynamic nature of the web, and new security threats targeting browser plugins make many of the old methods for displaying structures obsolete.

ChemWidget is a JavaScript/HTML5 application that has been designed to solve the problem of chemical communication on the web without plugins, Java or Flash. It works on equally well on desktops and touchscreen mobile devices, and enables our customers to build feature-rich, dynamic, chemically intelligent websites and applications.

No Java, No Flash, No Problem

All that is needed to get started with ChemWidget is a web browser. The main script file is a small, ~400K download, which means it is about as big as a mid-size JPEG image. The application is strongly cached by the user’s browser, so it is only re-downloaded if the user explicitly clears the browser cache, or when a new version of ChemWidget is deployed.

For your users, there are no confusing security warnings to click through, and no prompts to install a plugin or download Java. They can start viewing or drawing chemical structures as soon as the main page of your site or application loads. And everything works seamlessly on tablets and smartphones, too. ChemWidget was designed with mobile users in mind: most important UI elements are generously sized, making it easy to draw structures on a touch screen.

The structures you see on this page are not static images: they have been rendered by ChemWidget dynamically in your browser. Please visit our demo page to see more examples and try the editor application for yourself.
ChemWidget is a full-featured chemical editor that runs in your browser or on your tablet. It can render 7 types of chemical bonds, as well as ions, radicals and rings. All of this is done with pure JavaScript – no plugins needed. Try it for yourself and see why we believe ChemWidget is the easiest-to-use, best-looking, and best-performing chemical editor for the web. ChemWidget is under active development, so you can expect many exciting features to be rolled out soon.

Familiar Tools

Any chemist can be productive with ChemWidget right away. That is because the behavior of all the drawing and editing tools is industry-standard. There is absolutely no learning curve, even on touchscreen devices.


Good Chemistry

Do your structures include free radicals? Spiro rings? Double bonds with undefined E/Z geometry? A 19-carbon linear chain? Numbered R-groups? ChemWidget makes it easy to draw these features. It will even suggest best bond angles (i.e. 180° for C-C≣C) and warn of exceeding standard valence.


Smile for SMILES

ChemWidget generates SMILES strings right in the browser – no server communication required. SMILES can be explicitly requested by the user, or read programmatically with a JavaScript API call. A full implementation of CANGEN algorithm is used, so the generated SMILES strings are canonical.


Browser and Device Support

All major web browsers, including Internet Explorer, are fully supported. ChemWidget is touch-aware on iOS and Android. Most important UI elements are generously sized, making it easy to manipulate the structures on a touch screen.


Beautiful Structure Rendering

ChemWidget features publication-quality structure rendering. The “wedge” bonds connect seamlessly, and rendering of double bonds is adjusted automatically for best look and readability. ChemWidget is aware of Retina-class displays, and turns on pixel-doubling automatically on suitable devices.


Fast and Lean

ChemWidget was built for speed. In modern browsers, an HTML5 Canvas element is used for rendering, which results in a lightweight DOM structure and blazing-fast performance even with multiple structures on a page. The entire application fits in a small, ~400k download, which is strongly cached by the client browser.

ChemWidget runs in all modern web browsers and Internet Explorer* without additional downloads or plugins. Touch events are fully supported in iOS and Android browsers. ChemWidget supports Retina-class devices, such as the new iPad and MacBook Pro laptops.

Browsers Safari 5+, Firefox 3.6+, Chrome, IE8, IE9, IE10,** Opera 11+, iOS and Android 2+
Client Download Size Variable: 345K (WebKit, non-Retina) – 443K (IE8 and earlier)
Structure Import MDL/Symyx MOL V2
Structure Export MDL/Symyx MOL V2, SMILES (canonical)
API JavaScript: MOL import, SMILES and MOL export; CSS: look and feel
Server Communication Optionally available as a Vaadin 6 or 7 widget

* ChemWidget has been qualified for IE8 and IE9. Legacy versions of IE are known to work (with limitations), but are not specifically supported.
** IE10-specific touch events not supported
Chemwidget is free for academic, non-profit use.* A free, full-featured evaluation version is available for all commercial customers. Please contact our sales team if you require additional services, such as a custom visual theme that integrates with your existing website or corporate style.

Academic Government Industry
Single Site License** $0 $1099 $1099
Yearly Maintenance*** - $249 $249
Custom Development - Hourly Rate
* Please contact our sales team to apply for an academic license. A proof of academic status, such as .edu email, will be required. Maintenance contracts can only be purchased with commercial licenses
** Price for a single install site. Please contact our sales team for details about multi-site licenses. All license purchases include support for initial integration and one year of maintenance
*** Maintenance contracts ensure priority support and all major version upgrades for the duration of the contract