--- title: "Ubicloud vs StarSling: GitHub Actions runners" description: "Compare Ubicloud and StarSling GitHub Actions runners: runner labels, x64 and arm64 coverage, caching, billing and workflow optimization PRs." url: https://starsling.dev/compare/ubicloud canonicalUrl: https://starsling.dev/compare/ubicloud --- # StarSling vs Ubicloud runners for GitHub Actions - [How StarSling works](https://starsling.dev/) [Comparisons](https://starsling.dev/compare) / StarSling vs Ubicloud runners for GitHub Actions Last updated: 2026-09-27 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. ## Table of contents - [Head to head](#head-to-head) - [How Ubicloud runners work](#how-ubicloud-runners-work) - [Ubicloud cache and Docker layer caching](#ubicloud-cache-and-docker-layer-caching) - [Try StarSling on one Linux workflow](#try-starsling-on-one-linux-workflow) - [Workflow optimization you can inspect](#workflow-optimization-you-can-inspect) - [Best fit](#best-fit) - [Sources](#sources) - [References](#references) ## Head to head | Category | StarSling | Ubicloud | |---|---|---| | Selecting a runner | Yes, swap `ubuntu-latest` for `starsling-ubuntu-24.04`. | Swap `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 | Ubuntu 24.04 Linux runners. | x64 and arm64 Linux runners on Ubuntu 24.04 by default, with labels for Ubuntu 22.04 and 26.04. | | Hardware | 5th Gen AMD EPYC; 2-64 vCPU; unlimited concurrency. | AMD EPYC 9454P for standard x64 runners, AMD Ryzen 9 7950X3D for premium runners, and Ampere Altra for arm64. | | Caching | Keep GitHub Actions cache steps for the initial trial. AI optimization PRs can improve cache keys, dependency installs and build steps. | A transparent cache behind `actions/cache`, `actions/setup-*` caches and Docker `type=gha` layer caching, with 30 GB per repository per week. | | Billing model | Usage-based per-minute, from $0.004/min (2 vCPU) to $0.128/min (64 vCPU); queue time never billed; no seat fees. | Usage measured per minute and billed monthly. | | Runner images | The label names the OS version, `starsling-ubuntu-24.04`, so every run gets Ubuntu 24.04. | Built from the templates GitHub publishes in actions/runner-images, deployed a few days after GitHub's own release. | ## 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](/products/runners). 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](/github-actions-pricing) 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](/customers/mastra) and [Better Auth case study](/customers/better-auth) 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](/compare/runs-on) 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 - [Ubicloud: GitHub Actions integration quickstart](https://www.ubicloud.com/docs/github-actions-integration/quickstart), read 2026-09-28 - [Ubicloud: runner types](https://www.ubicloud.com/docs/github-actions-integration/runner-types), read 2026-09-28 - [Ubicloud: Ubicloud cache](https://www.ubicloud.com/docs/github-actions-integration/ubicloud-cache), read 2026-09-28 - [Ubicloud: pricing](https://www.ubicloud.com/docs/about/pricing), read 2026-09-28 - [Ubicloud home page](https://www.ubicloud.com/), read 2026-09-28 ## Other comparisons - [StarSling vs GitHub Actions](https://starsling.dev/compare/github-actions) - [StarSling vs Depot for GitHub Actions](https://starsling.dev/compare/depot) - [StarSling vs Blacksmith runners for GitHub Actions](https://starsling.dev/compare/blacksmith) - [StarSling vs WarpBuild](https://starsling.dev/compare/warpbuild) - [Buildkite vs GitHub Actions: where StarSling fits](https://starsling.dev/compare/buildkite) - [StarSling vs Namespace runners for GitHub Actions](https://starsling.dev/compare/namespace) - [StarSling vs RunsOn runners for GitHub Actions](https://starsling.dev/compare/runs-on) - [Compare GitHub Actions runners and CI platforms: StarSling vs GitHub-hosted, Depot, Blacksmith, WarpBuild, Buildkite, and Namespace](https://starsling.dev/compare) ## References - [StarSling Runners are now generally available](https://starsling.dev/blog/starsling-runners-are-now-generally-available) - [Launch YC: StarSling Runners - Self-Driving CI](https://www.ycombinator.com/launches/R7B-starsling-runners-self-driving-ci) - [StarSling docs](https://docs.starsling.dev) - [ci-speedup skill source (open source, MIT)](https://github.com/starslingdev/skills) - [ci-score skill source (open source, MIT)](https://github.com/starslingdev/skills/tree/main/skills/ci-score) - [ci-secure skill source (open source, MIT)](https://github.com/starslingdev/skills/tree/main/skills/ci-secure) - [What is AI-native CI?](https://starsling.dev/ai-native-ci) - [All StarSling comparisons](https://starsling.dev/compare) - [GitHub Actions alternatives](https://starsling.dev/github-actions-alternatives) - [GitHub Actions pricing](https://starsling.dev/github-actions-pricing) - [Self-hosted GitHub Actions runners](https://starsling.dev/self-hosted-github-runners) - [Benchmark on your own workflows](https://docs.starsling.dev/performance/benchmarks) - [Migration guide](https://docs.starsling.dev/configuration/migration-guide) - [Runner label reference](https://docs.starsling.dev/configuration/label-reference) - [Runner instance types](https://docs.starsling.dev/runners/instance-types) - [Install the /ci-speedup skill to fix slow GitHub Actions](https://starsling.dev/skills/ci-speedup) - [Install the /ci-score skill to improve your GitHub Actions setup](https://starsling.dev/skills/ci-score) - [Install the /ci-secure skill to close critical attack vectors in GitHub Actions](https://starsling.dev/skills/ci-secure)