We raised $3M for agent-native runners
Pricing
Products
Skills
Resources
Get Started

StarSling vs Ubicloud runners for GitHub Actions

StarSling is AI-native CI for GitHub Actions: drop-in Ubuntu runners plus agents that open optimization PRs for your workflows.

Ubicloud runs managed GitHub Actions runners on x64 and arm64 Linux, selected with a one-line label change and billed per minute. StarSling runs managed Ubuntu runners and adds AI agents that open workflow optimization PRs. Choose around the architectures you need and how you want to improve the workflow. For new accounts, AI-powered optimization PRs are only available to customers on paid plans and are not enabled by default.

View in Markdown
Selecting a runner
How StarSling works

Last updated 2026-09-27

Head to head

Selecting a runner
StarSlingYes, swap ubuntu-latest for starsling-ubuntu-24.04.
UbicloudSwap ubuntu-latest for a label such as ubicloud-standard-2. The number is the vCPU count, -arm selects arm64, and -ubuntu-2204 selects Ubuntu 22.04.
Operating systems
StarSlingUbuntu 24.04 Linux runners.
Ubicloudx64 and arm64 Linux runners on Ubuntu 24.04 by default, with labels for Ubuntu 22.04 and 26.04.
Hardware
StarSling5th Gen AMD EPYC; 2-64 vCPU; unlimited concurrency.
UbicloudAMD EPYC 9454P for standard x64 runners, AMD Ryzen 9 7950X3D for premium runners, and Ampere Altra for arm64.
Caching
StarSlingKeep GitHub Actions cache steps for the initial trial. AI optimization PRs can improve cache keys, dependency installs and build steps.
UbicloudA transparent cache behind actions/cache, actions/setup-* caches and Docker type=gha layer caching, with 30 GB per repository per week.
Billing model
StarSlingUsage-based per-minute, from $0.004/min (2 vCPU) to $0.128/min (64 vCPU); queue time never billed; no seat fees.
UbicloudUsage measured per minute and billed monthly.
Runner images
StarSlingThe label names the OS version, starsling-ubuntu-24.04, so every run gets Ubuntu 24.04.
UbicloudBuilt from the templates GitHub publishes in actions/runner-images, deployed a few days after GitHub's own release.
Get Started For Free 

How Ubicloud runners work

Ubicloud installs as the Ubicloud Managed Runners GitHub App. A job moves to Ubicloud when its runs-on label changes from ubuntu-latest to a Ubicloud label such as ubicloud-standard-2, and each job gets an isolated, clean and ephemeral VM.

Ubicloud's docs place the managed runner VMs across data centers in Germany. Ubicloud's source code is available under the AGPL license, so a team can also run the software itself.

Ubicloud cache and Docker layer caching

Ubicloud's transparent cache serves actions/cache, the package-manager caches in actions/setup-*, and Docker layer caching through type=gha, with 30 GB of cache storage per repository per week. Ubicloud recommends the transparent cache, and its older ubicloud/cache action is a drop-in replacement for actions/cache.

When moving a workflow between providers, list those cache actions next to the runner label, and restore GitHub Actions caching where the trial needs it.

Try StarSling on one Linux workflow

Choose a representative Ubuntu job with a clear success condition. Keep the same commit, tests and build outputs across the comparison, and record queue time separately from execution time.

  • Install the StarSling GitHub App for the trial repository, then choose a label from StarSling runner sizes. The default starsling-ubuntu-24.04 selects 4 vCPU; match the size to the Ubicloud label you are comparing.
  • Prepare a small workflow PR. Where the job uses ubicloud/cache, switch it back to actions/cache in the same PR. Preserve required check names, permissions and test commands.
  • Run repeated cold-cache and warm-cache trials. Compare completed work, error rate, queue time, execution time and billed usage. Use the GitHub Actions pricing guide to compare the cost of your actual workload.
  • Keep the original workflow revision available. Roll back the trial by reverting the runner label and any cache edits together.

Workflow optimization you can inspect

Read the public Mastra optimization PRs and results and Better Auth case study to see changes to real workflows, the measured windows and the work behind each result. Use those examples to identify a testable improvement in your own pipeline.

For new accounts, AI-powered optimization PRs are only available to customers on paid plans and are not enabled by default.

Best fit

Choose StarSling if

Teams running Ubuntu GitHub Actions jobs who want managed runners and reviewable PRs that improve the workflow's caching, installs and test execution. For new accounts, AI-powered optimization PRs are only available to customers on paid plans and are not enabled by default.

Choose Ubicloud if

Teams that want managed x64 and arm64 Linux runners with a transparent cache, or an open-source runner stack they can host themselves.

FAQ

Can I move from Ubicloud to StarSling by changing runs-on?

Start with an Ubuntu job and a StarSling label. If the workflow uses ubicloud/cache, switch it back to actions/cache in the same trial PR. Test the resulting workflow and keep the original revision for rollback.

How should I compare Ubicloud, RunsOn and StarSling?

Start with the architectures you need, where the compute should run and how each one bills, then run the same job on matched resources. This page covers Ubicloud; StarSling vs RunsOn runners for GitHub Actions covers RunsOn. Measure runtime and total cost across repeated cold-cache and warm-cache runs before choosing.

Does installing StarSling enable AI optimization PRs?

For new accounts, AI-powered optimization PRs are only available to customers on paid plans and are not enabled by default.

Sources

Other comparisons

Compare StarSling with the other runner and CI options teams evaluate.

References

Get started

Try the AI-native runner.

One line to install. Faster runs on day one, and agents that keep optimizing your pipeline through reviewable PRs.

Get Started For Free Install the ci-speedup skill