Latest version: CASA 6.5

The Release Notes and Known Issues of the 6.5 release are available in

CASA 6.5 is based on Python 3, and available either as a downloadable tar-file distribution with Python environment included, or as a modular version that can be installed with pip-wheels.

Manual processing can be done with any CASA version, but ALMA and VLA pipelines may differ and are not always included, so download the correct CASA version for pipeline use.


 Linux     
(RedHat 6, 7, 8)
 Mac     
(OS 11, OSX 10.14, 10.15)
General Use
CASA 6.5.2 (RH7/8 - Py 3.8) CASA 6.5.2 (RH7 - Py 3.6) CASA 6.5.2 (OS11 - Py 3.8)
CASA 6.5.2 (OS11 - Py 3.6)
ALMA Pipeline

(Notes) ALMA: Version CASA 6.4.1-12, includes a pipeline validated for ALMA (pipeline version 2022.2.0.64).

For more information, see the ALMA Science Pipeline website.
CASA 6.4.1 (RH7/8) CASA 6.4.1 (OS11)
CASA 6.4.1 (10.15)
VLA Pipeline

(Notes) VLA: Version CASA 6.2.1-7, includes a pipeline validated for the VLA (pipeline version 2021.2.0.128).

For more information, see the VLA Science Pipeline website.
CASA 6.2.1 (RH6/7) CASA 6.2.1 (10.15)
CASA 6.2.1 (10.14)

The above CASA versions can also be downloaded from our NAOJ CASA mirror site and NAOJ CASA-pipeline mirror site, or via Google Drive.


While the CASA version listed above are built on Linux RedHat and Mac OS, they are expected to work for mutiple LINUX and Mac computer operating systems, including certain Ubuntu versions. In CASA Docs we list a compatibility matrix, which shows the different Operating Systems and Python versions on which current and future CASA versions are expected to work, and for which the CASA team accepts bug reports.

However, note that CASA is only fully validated against the operational configuration of NRAO instruments (currently RHEL7/Python 3.6).

See 'Version Support' below for more details.


CASA 6: pip-wheel installation

CASA 6 can optionally be installed through modular pip-wheels, with the flexibility to build CASA tools and tasks into a customized Python environment. Instructions on how to install the pip-wheel version of CASA 6 can be found in CASA Docs: CASA 6 Installation

The modular pip-wheel version is not yet used in production by ALMA and VLA, and does not include any pipelines.







Pre-release versions of CASA can be found here (see also this download through Google Drive). Pre-release versions reflect ongoing CASA development and are not supported. Use at your own discretion.




CASA 6.5 is fully validated against the operational configuration of NRAO instruments, currently RHEL7 with Python 3.6. Furthermore, automated verification tests and manual package testing have been performed for the following operating systems:
  • Linux RedHat 7
  • Mac OS 11 (Big Sur, x86 Intel)
  • Mac OSX 10.15 (Catalina)
Other system that we expect CASA to work on, including certain versions of Ubuntu, are listed in the compatibility matrix on CASA Docs. CASA accepts bug reports for all combinations of OS and Python that are listed there.

Mac M1: CASA for Mac OS is officially supported for x86 Intel chips. At this moment, the CASA team does not have the resources or infrastructure in place to produce, test, and support CASA packages for machines with the ARM-based M1 chips. Nevertheless, automated testing shows that CASA tasks and tools work on M1 machines. We therefore recommend that users with M1 machines should use the OS 11 x86 packages or pip-wheels to run CASA in those machines, and report any problem to casa-feedback@nrao.edu.

Mac OS 12: We recommend that users of Mac OS 12 (either x86 or M1 based) use the OS 11 x86 package to run CASA in those machines, and report any problem to casa-feedback@nrao.edu. Warning: the CASA viewer may not work properly on Mac OS 12. We recommend users to use the CARTA visualization software instead.

Other LINUX: CASA may also work on other flavors of Linux, but this is at the discretion of users. Some tips from the community can be found here.




NRAO has installed a suite of CASA and pipeline versions for local users, visitors, and users who request remote access to NRAO machines. More information on running CASA locally at NRAO can be found here.




To efficiently run CASA, a balanced hardware configuration regarding memory, processing power and file I/O may be required. Recommendations on the CASA hardware requirements for VLA and ALMA data can be found on this 'Hardware Requirements' page.



DISCLAIMER: CASA now collects usage statistics including task execution timings and crash reports. This data will be periodically sent back to NRAO to guide future priorities and decision making. All collection is anonymous and contains no scientific or personal data. For more information, or instructions on how to disable telemetry recording, see CASA Docs