Prometheus
Tenable
| Feature | Prometheus | Tenable |
|---|---|---|
| Pricing | Free only | Free / from $3990/mo |
| Free Plan | ✓ Yes | ✓ Yes |
| Rating | 4.5 / 5 | 4.3 / 5 |
| Best For | devops-engineers, sre-teams, kubernetes-users, infrastructure-teams | security-teams, compliance-officers, it-operations, vulnerability-managers |
| Founded | 2012 | 2002 |
| Metrics Collection | ✓ | ✗ |
| Alerting | ✓ | ✗ |
| Promql | ✓ | ✗ |
| Service Discovery | ✓ | ✗ |
| Grafana Integration | ✓ | ✗ |
| Multi Dimensional Data | ✓ | ✗ |
| Vulnerability Scanning | ✗ | ✓ |
| Asset Discovery | ✗ | ✓ |
| Risk Prioritization | ✗ | ✓ |
| Compliance Reporting | ✗ | ✓ |
| Web App Scanning | ✗ | ✓ |
| Cloud Security | ✗ | ✓ |
✓ 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
✓ Tenable Pros
- Comprehensive vulnerability coverage
- Excellent asset discovery
- Good risk prioritization
- Strong compliance reporting
✗ Tenable Cons
- Expensive for large environments
- Complex initial setup
- Scanning can impact performance
The Verdict
Prometheus is built for devops engineers and sre teams, with a focus on metrics-collection and alerting. Tenable targets security teams and compliance officers and leads with vulnerability-scanning and asset-discovery.
Prometheus uses custom enterprise pricing, while Tenable starts at $3990/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.