Chimera/ChimeraX Commercial Licensing

UCSF Chimera and UCSF ChimeraX are licensed commercially based on a non-exclusive, nontransferable, 3-year license. For-profit entities must execute a license agreement to gain access. The two programs are licensed separately from each other, and no free trial licenses are offered.

** We apologize that due to current circumstances beyond our control (departmental and university-level staffing issues), commercial license query response times and processing may be slow.**

Chimera vs. ChimeraX:
The capabilities of the two programs overlap significantly but not completely, and where features overlap, they may still differ in detail. Many people currently use both programs. However, if you are trying to choose between the two, here are some considerations. ChimeraX has much better performance with large structures, as well as other major advantages and completely new features. Perhaps most importantly, ChimeraX is under active development and includes a significant subset of Chimera features (with more to come, see the missing features list). Chimera, on the other hand, has effectively reached end-of-life, is no longer being developed, and is only updated for critical maintenance purposes. In addition, a few Chimera tools that rely on web services may stop working in the future because the infrastructure they depend on is obsolete (details...), whereas ChimeraX uses newer software frameworks that extend its life far into the future. For full lists of included tools and commands, see the User Guides: [Chimera] [ChimeraX].

Licensing Costs:
Costs are based on the number of users per Company Site:

These non-refundable fees are assessed per site and do not include a company's affiliates or subsidiaries. Each company site, affiliate, or subsidiary must acquire a separate license. The licenses last for 3 years from the date of issuance.

Licenses are assigned to specific named individuals, rather than floating among a larger set of people. For a given user based at a given site, however, there are no restrictions on the number of downloads during the 3-year period of the license; the user could have installations on multiple computers and/or different versions of the program on the same computer (production release, different daily builds, etc.). It is possible to reassign the license to a different user if, for example, someone leaves the company, but we require notification ( of changes in the assigned user (1-user) or primary user (6-user or unlimited users). For a 6-user license, the company is responsible for maintaining its own list of the assigned individuals and ensuring that the number does not exceed six, but we do not need notification unless the primary user is changed.

License Agreement Process:

  1. If your company is interested in pursuing a license agreement, please complete this form to begin the process. Please complete all fields. A PDF of the license agreement with this information along with a quote will be sent to the primary point of contact included on the form.

  2. After receiving the quote, the client (you or other company representative) should generate and send a purchase order to

  3. We will invoice the client under the purchase order.

  4. Client should send payment via ACH or bank wire transfer (checks are not accepted) and notify Instructions can be found on page 2 of all invoices. Please be sure to include your invoice number on the reference/memo field to help expedite posting of your payment to your order.

  5. After we confirm receipt of payment, the license key and software download instructions will be be emailed to the primary user, who is then responsible for sharing them with the other users (if any) covered by the license. The license key will expire no less than 3 years from the date of issuance, even if that is significantly later than the “effective date” in the license agreement. To avoid gaps in availability, a license can be renewed by contacting us to extend the agreement and submitting payment to obtain a new key before the previous one expires.

System Requirements:
Downloads are available for recent versions of the Windows and macOS operating systems and some Linux distributions; other versions may not be supported. Chimera and ChimeraX are graphics-intensive programs intended for local, interactive use. We do not provide support for using them on compute clusters or virtual machines, or for remote display or remote rendering (details...).

Revised 29-Nov-2022