Blacksmith vs GitHub Actions: A Fair Comparison

Blacksmith vs GitHub Actions is a slightly odd comparison, because Blacksmith does not replace GitHub Actions: it runs your Actions jobs on its own hardware. You keep your workflows, your GitHub repository and your pull request experience, and you change where the jobs execute. This guide explains what that means, compares pricing from public pages, and says when each option fits. Facts were checked on 2026-10-11 against public pages, and they change, so verify before you buy.

What Blacksmith is

Blacksmith is a third-party provider of GitHub Actions runners. You install its GitHub App and change runs-on from ubuntu-latest to a Blacksmith label. Its public site describes faster hardware and also other features, such as its own cache and Docker build caching with sticky disks. It sits in the same category as other runner providers; see faster GitHub Actions runners for the full list.

jobs:
  test:
    # GitHub-hosted
    # runs-on: ubuntu-latest
    # Provider label (check the provider docs for the exact name)
    runs-on: blacksmith-4vcpu-ubuntu-2404

Label names are provider-specific, so take them from its documentation, not from here.

What GitHub-hosted runners are

The default: runners managed by GitHub. Standard Linux runners have 2 vCPUs and are $0.006 per minute on private repositories, after your plan's included free minutes. Larger runners (4, 8, 16 cores and up) are billed per minute with no free minutes, for example Linux 8-core at $0.022 per minute (GitHub list prices checked 2026-10-10). Public repositories can use standard runners at no charge. See GitHub Actions pricing explained.

Pricing model compared

Because the unit is the same, the real question is cost per job: price per minute multiplied by minutes taken. A cheaper minute helps you if the job runs at least as fast. A faster machine at the same price helps you even more. The only way to know is to run your own workflow on both. Use the Actions cost calculator to model GitHub's side and the CI minutes forecaster to project monthly usage.

When GitHub-hosted is the better fit

• Your CI is light: a few thousand minutes a month, mostly within free minutes.
• You want the fewest vendors, a single bill and one security review.
• You need GitHub-specific features such as larger runners with static IP ranges or Azure private networking managed in one place.
• Your jobs wait on network or external services, where a faster CPU does not matter.

When a provider like Blacksmith is the better fit

• You are paying for many CPU-bound minutes, such as compiles and large test suites, and want lower per-minute rates.
• You want faster hardware without running machines yourself.
• You value extras such as a faster cache or Docker layer caching, and they work for your build.
• You are happy to add a vendor in the CI path and have checked its security and support terms.

Things to ask any runner provider

1. What is the exact vCPU, RAM and CPU generation behind the label?
2. How does the cache work, and what are its limits?
3. What happens during an outage: do jobs queue, fail or fall back to other runners?
4. Where does the code run, and how is it isolated between customers?
5. Is there a trial on your own repository so you can measure?

One more option

compiler.dev is another runner option on the same model. It was faster than GitHub's 2-core runner on 15 of 19 benchmarked stacks, by 1.1 to 3 times, with Linux 8 vCPU at $0.009 per minute and macOS M4 Pro at $0.028 per minute. It falls back automatically to your own runners, and its comparison mode measures your own jobs. We have not benchmarked Blacksmith against it here, and we are not claiming one is faster than the other; run your jobs on both if you are shortlisting.

Before you pay anyone

Make sure the free fixes are in place: caching, concurrency cancels and test sharding. They shrink the minutes you buy from anyone. The slow CI hub lists them all, and GitHub Actions alternatives covers moving off Actions entirely.

FAQ

Is Blacksmith an alternative to GitHub Actions?

No, not exactly. It is a runner provider for GitHub Actions. Workflows, triggers and the Actions UI stay the same, and only the machines change.

Is Blacksmith cheaper than GitHub Actions?

Its listed per-minute price for 2 vCPU Ubuntu is lower than GitHub's standard runner, as of 2026-10-11. Total cost depends on how long your jobs take on each, so measure.

Can I use both?

Yes. Many teams put heavy jobs on a provider and leave small jobs on GitHub-hosted runners, because runs-on is set per job.

Do I need to change my workflows?

Usually only the runs-on label, plus any steps that depend on provider-specific features.