GitHub doubles the default runner for public repositories

GitHub has completed a fleet-wide upgrade of the hosted runners used for GitHub Actions in public repositories. Workflows on Linux or Windows that use GitHub's default runner labels will now execute on 4-vCPU virtual machines instead of the previous 2-vCPU instances. The new runners also come with 16 GiB of memory, double the old allotment.

The rollout began on December 1, 2023, and applies automatically. Developers do not need to change any workflow configuration to take advantage of the new hardware. In real-world usage during the gradual deployment, GitHub observed roughly a 25% performance improvement for typical CI/CD workloads on the upgraded machines.

What changed for open source maintainers

GitHub Actions has been free for public repositories since its launch in 2019, but the underlying infrastructure had remained at 2-vCPU machines until this upgrade. The larger runners benefit projects that compile large codebases or run memory-intensive test suites: workflows should complete faster, and workloads that previously approached the 8 GiB memory ceiling on the older machines now have twice as much headroom.

The storage capacity for these runners has also been increased, with the new machines offering 10 times the storage of the previous generation. For the open source ecosystem, this represents a meaningful reduction in build wait times and a faster feedback loop on pull requests.

"GitHub is the home for the open source community, so I'm thrilled we've been able to give all open source projects access to Linux and Windows machines that have twice the v-CPUs, twice the memory and 10 times the storage for their builds, for free," said Martin Woodward, GitHub's vice president of developer relations. "This investment will give valuable time back to the maintainers of open source projects who benefited from over 7 billion build minutes with GitHub Actions in the past year alone."

No action required

Public repositories running workflows with any of the existing Ubuntu or Windows hosted runner labels will automatically get the new 4-core machines starting today. No changes to workflow files, runner selection, or billing settings are needed. The upgrade is entirely transparent to developers, and the performance gains are available immediately.