Semaphore CI
Cloud-based CI/CD with credit-based compute, 20 concurrent jobs on the free tier, native Docker support, and YAML pipelines for web and backend projects.
Use Cases
Free Tier
$15 compute credits/month (~2,000 Ubuntu x64 2-vCPU minutes), 20 concurrent jobs, 9.6 GB cache/project, 20 GB/month artifact egress
How to Maximize the Free Tier
Your $15 monthly credit is the hard cap and refills monthly, so monitor usage in the billing dashboard. With 20 concurrent jobs you can split a large test suite across parallel jobs to finish in minutes, but each job burns credits proportional to runtime and machine size — stick to default 2-vCPU x64 machines and reserve larger ones for heavy builds. The 9.6 GB per-project cache is your best credit saver: cache dependencies so builds skip re-installs. Watch the 20 GB/month free artifact egress; download large release binaries promptly or push them to external storage. Combine with GitHub for free repo hosting and add a status badge to your README.
Getting Started
Sign up at semaphore.io and connect your GitHub or Bitbucket repo → Semaphore auto-detects your stack and proposes a starter pipeline → review the generated .semaphore/semaphore.yml and adjust jobs → enable caching in the pipeline config → push a commit to trigger the first run → add a status badge to your README from repo settings.
Pros
- High concurrency: 20 parallel jobs on the free tier is exceptional for fan-out test matrices
- Credit flexibility: Credits let you occasionally run larger machines without a plan change
- Fast feedback: Parallel execution can finish a 10-minute test suite in under a minute when split well
Cons
- Credit anxiety: $15/month is a hard budget — a single long-running job or large machine eats a big chunk
- Linux-focused free tier: No free macOS or Windows runners; mobile or Windows builds need paid machines
- Artifact egress cap: 20 GB/month free egress can be tight if you publish large binaries regularly