Google Container-Optimized OS (COS)

google os

Google Container-Optimized OS (COS) is an operating system image for GCP Compute Engine VMs which is optimized for running Docker containers. It is maintained by Google and is based on the open source Chromium OS project.

Release Released Support Status Latest
109 (LTS) 9 months ago
(27 Sep 2023)
Ends in 1 year and 1 month
(01 Sep 2025)
(07 Nov 2023)
105 (LTS) 1 year and 3 months ago
(03 Apr 2023)
Ends in 8 months and 4 weeks
(01 Apr 2025)
(07 Nov 2023)
101 (LTS) 1 year and 9 months ago
(15 Sep 2022)
Ends in 1 month and 3 weeks
(01 Sep 2024)
(07 Nov 2023)
97 (LTS) 2 years and 3 months ago
(29 Mar 2022)
Ended 4 months ago
(01 Mar 2024)
(07 Nov 2023)
93 (LTS) 2 years and 8 months ago
(18 Oct 2021)
Ended 9 months ago
(01 Oct 2023)
(24 Oct 2023)
89 (LTS) 3 years ago
(07 Apr 2021)
Ended 1 year and 4 months ago
(01 Mar 2023)
(03 Apr 2023)
85 (LTS) 3 years and 9 months ago
(24 Sep 2020)
Ended 1 year and 10 months ago
(01 Sep 2022)
(22 Aug 2022)
81 (LTS) 4 years ago
(27 Mar 2020)
Ended 2 years and 10 months ago
(01 Sep 2021)
(10 Jan 2022)
77 (LTS) 4 years and 9 months ago
(27 Sep 2019)
Ended 3 years ago
(01 Apr 2021)
(11 Jan 2021)
73 (LTS) 5 years ago
(25 Mar 2019)
Ended 4 years ago
(01 Jun 2020)
(05 Sep 2020)
69 (LTS) 5 years and 9 months ago
(18 Sep 2018)
Ended 4 years and 7 months ago
(01 Dec 2019)
(08 Oct 2019)

Support policy

Container-Optimized OS is tested and qualified for running various container workloads on Google Cloud. It is actively patched with security updates (CVEs) and bug-fixes to address issues that impact Google Cloud users. Users get access to these fixes via image releases in the cos-cloud project.

Container-Optimized OS image support is available for Long Term Supported (LTS) family of images in the cos-cloud project. A description of available image families is available at the Versioning Scheme doc. The following support commitment applies only to the LTS family of images.

Support duration

Approximately twice each year, the Container-Optimized OS team releases a Long Term Supported (LTS) milestone on its cos-[MILESTONE]-lts and cos-arm64-[MILESTONE]-lts image families. Once a milestone is introduced on the LTS families, it is supported for 2 years.

During this support window:

  • The milestone is actively patched for any critical bugs.
  • The milestone is actively scanned for security vulnerabilities, and security fixes are applied on regular basis.
  • New releases containing high priority bug and security fixes are released on-demand.
  • New releases containing medium and low priority bug and security fixes are released every 3 months.
  • To maintain stability, no new breaking features are introduced.
  • All changes in the image are documented on a dedicated release notes page.


At the end of a milestone’s support window, the corresponding cos-[MILESTONE]-lts and cos-arm64-[MILESTONE]-lts families are deprecated. Specifically, the DEPRECATED flag is set on images in that milestone and those images stop appearing in the active list of images in the cos-cloud project.

Warning: Any Image Family API references to the deprecated image family will return errors and break any workflows depending on it. You should not use this API to create production instances.

Deprecated images are still accessible and usable when accessed directly by name using the images get API. However, any issues with those images might not be fixed or will only be fixed in newer milestones. Issues reported against deprecated images may be fixed only in newer image milestones.

More information is available on the Google Container-Optimized OS (COS) website.

You should be running one of the supported release numbers listed above in the rightmost column.

You can check the version that you are currently using by running:
cat /etc/os-release /etc/lsb-release

You can submit an improvement to this page on GitHub :octocat: . This page has a corresponding Talk Page.

A JSON version of this page is available at /api/cos.json. See the API Documentation for more information. You can subscribe to the iCalendar feed at /calendar/cos.ics.