How to check the runner image that will be used before a workflow starts?

[ixfd64]

Why are you starting this discussion?

Question

What GitHub Actions topic or product is this about?

Actions Runner Image

Discussion Details

Is there a way to check which specific runner image will be used before a workflow is run?

Google directs me to the releases page, but my understanding is there is a lag of a few days between when a release is created and when it goes live.

[44erxyz]

You can’t check the exact runner image version that will be used ahead of time, but you can check the version that is currently live at the start of a workflow.

A couple of options:

Log the image version inside your workflow
GitHub Actions publishes the image build version as an environment variable on hosted runners. You can expose it with a simple step:

jobs:
check-runner:
runs-on: ubuntu-latest
steps:
- name: Show runner image info
run: |
echo "Image release: $ImageVersion"
echo "Image release URL: $ImageOS"

This will tell you which exact image release your job got.

Check the live image rollout docs
The actions/runner-images releases page
lists the latest published images.

When a release is created there, it doesn’t go live instantly — there’s usually a lag of a few days for rollout.

The “image release rollout” documentation
explains the delay and how images propagate.

Use actions/runner-images issue tracker for rollout status
The team often posts updates about rollout progress in release notes or pinned issues. If you need to know whether a new image is live yet, that’s the most reliable place.

👉 In short: you can’t know in advance which image your workflow will use, only which one it did use once the job starts. If you need consistency, the recommended approach is to pin to a container image or self-hosted runner instead of relying on ubuntu-latest/windows-latest.

[ixfd64]

Thanks for the response. I was afraid this was the case.

However, I do have two more questions:

1. I was told that GitHub does not support specifying a specific runner image version. Was this recently changed?
2. Why do some images take longer to become "live" after release? For example, the current macos-14 image is still from September 1, yet the macos-15-arm image from September 11 is already in use.