Everyone's chasing the shiny managed CI. Let's talk real numbers for a change.
At 10k builds/month, self-hosting is almost always cheaper if you have the infra. A c2-standard-4 runner on GCE is about $140/month. GitLab Runner is free. Your real cost is maintenance, maybe 2-3 hours a month. That's it.
GitHub Actions? Let's do the math. Assume your builds use 3 vCPUs and run for 10 minutes each on Linux. That's 10,000 * 10 * 3 = 300,000 compute minutes. You get 3,000 free minutes. So you pay for 297,000 minutes. At $0.008 per minute, that's **$2,376/month**. Even with their "free" minutes, you're paying over 15x more.
The catch? You need to manage the runner. But if you're already in GCP or AWS, it's trivial.
```yaml
# Your self-hosted runner config. That's it.
concurrent = 10
check_interval = 0
[session_server]
session_timeout = 1800
```
The "value" isn't in the invoice, it's in not paying for overpriced compute.
SQL is enough
I'm a community moderator for a B2B SaaS vendor, and our team of about 50 developers uses self-hosted GitLab Runners on our own Kubernetes cluster to handle builds for our core platform.
**Core Comparison**
1. **Cost at Scale**: The OP's math is directionally correct. At 10k builds, GitHub Actions compute charges are a real line item, often $2k+. With self-hosted, your cost is essentially your cloud VM or node expenditure, which for comparable compute can be 80-90% lower. The hidden cost is ~2-4 engineering hours monthly for upkeep.
2. **Operational Overhead**: Self-hosted demands maintenance: runner version upgrades, security patches, and debugging failed agent registrations. GitHub Actions removes that completely. If your team lacks platform or DevOps bandwidth, that saved time has tangible value.
3. **Performance Control**: With your own runners, you control machine type, disk, and network. You can use fast local SSDs or high-CPU instances. In my environment, builds with large dependencies run about 40% faster on our tuned runners versus the standard GitHub hosted hardware due to persistent caches.
4. **Vendor Lock-in & Portability**: GitHub Actions workflows are largely proprietary. Migrating to another system requires rewriting pipelines. GitLab CI/CD syntax runs on any GitLab instance or can be adapted to other runners more easily. If multi-cloud or on-prem futures are a concern, this matters.
**My Pick**
I'd recommend self-hosted GitLab Runner for teams that already have committed cloud infrastructure and some platform engineering capacity. The cost savings are too significant to ignore at this volume. If your team is lean and prioritizes moving fast over cost optimization, GitHub Actions is the simpler choice. To make the call clean, tell us: what's your team's tolerance for infrastructure maintenance, and is your build process fairly standard or does it require specific hardware/network setups?
Keep it constructive.
Wow, thanks for breaking down the numbers! That $2,376 vs $140 is a huge difference. I'm still learning the ropes and have been trying to decide between the two for my side project.
One thing I'm worried about - you said 2-3 hours a month for maintenance. Is that realistic for a total beginner? I've only set up a basic Docker container before, not a GitLab Runner. What about things like network egress costs if the runner pulls large images from a registry? Or if the runner goes down at 2am and I'm bad at monitoring? Would love to know if there's a simple way to get started without the risk of waking up to a broken pipeline.