Prometheus
Semaphore
| Feature | Prometheus | Semaphore |
|---|---|---|
| Pricing | Free only | Free / from $10/mo |
| Free Plan | ✓ Yes | ✓ Yes |
| Rating | 4.5 / 5 | 4.3 / 5 |
| Best For | devops-engineers, sre-teams, kubernetes-users, infrastructure-teams | development-teams, open-source-projects, startups, monorepo-users |
| Founded | 2012 | 2012 |
| Metrics Collection | ✓ | ✗ |
| Alerting | ✓ | ✗ |
| Promql | ✓ | ✗ |
| Service Discovery | ✓ | ✗ |
| Grafana Integration | ✓ | ✗ |
| Multi Dimensional Data | ✓ | ✗ |
| Parallel Pipelines | ✗ | ✓ |
| Test Reports | ✗ | ✓ |
| Secrets Management | ✗ | ✓ |
| Docker Support | ✗ | ✓ |
| Caching | ✗ | ✓ |
| Notifications | ✗ | ✓ |
✓ Prometheus Pros
- Free and open-source
- Powerful query language
- Great Kubernetes integration
- Active community
✗ Prometheus Cons
- No built-in long-term storage
- Complex setup
- Steep learning curve
✓ Semaphore Pros
- Extremely fast build times
- Generous free tier for open source
- Easy YAML-based configuration
- Built-in secrets management
✗ Semaphore Cons
- Smaller community than GitHub Actions
- Limited marketplace for pre-built steps
- Debugging failed builds can be tricky
The Verdict
Prometheus is built for devops engineers and sre teams, with a focus on metrics-collection and alerting. Semaphore targets development teams and open source projects and leads with parallel-pipelines and test-reports.
Prometheus uses custom enterprise pricing, while Semaphore starts at $10/mo — a tangible advantage for teams with a fixed budget.
Both offer free plans, so you can test each with your real workflow before committing to a subscription.
This is a genuinely close comparison. If you can, sign up for both free trials (where available) and run a one-week test with your actual team tasks before deciding.