Cortex vs Thanos
A side-by-side comparison of two self-hosted monitoring & status options — licensing, setup difficulty, resource needs, and what each one replaces.
Thanos
Highly available Prometheus setup with long-term storage
| Feature | Cortex | Thanos |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 90 · Excellent | 94 · Excellent |
| Category | Monitoring & Status | Monitoring & Status |
| License | Apache-2.0 | Apache-2.0 |
| Language | Go | Go |
| Setup difficulty | Hard | Hard |
| Min. RAM | 1,024 MB | 1,024 MB |
| Deployment | docker, kubernetes, helm | docker, kubernetes, helm |
| GitHub stars | ★ 5,865 | ★ 14,214 |
| First released | 2016 | 2018 |
| Replaces | Datadog, Grafana Cloud | Datadog, Grafana Cloud |
What are Cortex and Thanos?
Cortex
Cortex provides a horizontally scalable, highly available, multi-tenant, long-term store for Prometheus metrics. It offers a single API endpoint for querying and writing time series data across clusters.
- Multi-tenant metrics storage
- Horizontally scalable
- Prometheus-compatible API
- Long-term retention
Thanos
Thanos extends Prometheus with global query view, unlimited retention, and high availability. It uses object storage to keep metrics cheaply for years while presenting a single query endpoint across many Prometheus instances.
- Global query view
- Unlimited metric retention
- Object storage backend
- Downsampling for fast queries
Cortex vs Thanos: key differences
Both projects are written in Go. Cortex is the more established project (first released 2016), while Thanos arrived in 2018. Thanos has the considerably larger community, at 14,214 GitHub stars versus 5,865.
Why pick each one
Choose Cortex if…
- Built for very large scale
- True multi-tenancy
Watch out for
- Operationally heavy
- Overkill for small setups
Choose Thanos if…
- Scales Prometheus to massive deployments
- Cheap long-term storage
Watch out for
- Complex multi-component architecture
- Steep learning curve
Frequently asked questions
Is Cortex or Thanos better?
Neither is universally better. Thanos has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Cortex and Thanos free and open-source?
Yes. Cortex is licensed under Apache-2.0 and Thanos under Apache-2.0. Both can be self-hosted at no software cost.
Can I run Cortex and Thanos with Docker?
Cortex: yes. Thanos: yes.