Thanos vs Grafana Mimir
Prometheus long-term storage — sidecar-bolted vs. ground-up multi-tenant
| Thanos | Grafana Mimir | |
|---|---|---|
| Summary | CNCF-graduated long-term storage and global query layer for Prometheus, backed by object storage. | Grafana Labs' horizontally scalable, multi-tenant Prometheus-compatible long-term metrics store. |
| License | Apache-2.0 | AGPL-3.0 |
| Language | Go | Go |
| GitHub stars (approx) | 14000 | 5000 |
| Categories | metrics | metrics |
| Replaces SaaS | datadog, new-relic | datadog, new-relic |
| Self-host deployment | kubernetes helm, docker, single binary per component | kubernetes helm, jsonnet, docker |
| Commercial hosted option | no / self-host only | yes (vendor-run) |
| Repository | https://github.com/thanos-io/thanos | https://github.com/grafana/mimir |
| Freshness checked | 2026-05-17 | 2026-05-17 |
When to prefer Thanos
You already run Prometheus and want object-storage-backed long-term retention with minimal new components. Thanos bolts onto existing Prometheus servers via a sidecar, which is the least invasive way to get HA + global view + cheap S3 retention.
When to prefer Grafana Mimir
You are building a multi-tenant Prometheus-compatible platform from scratch, or you want a single distributed system rather than the Thanos sidecar pattern. Mimir is Grafana Labs's evolution of Cortex — designed for high-scale multi-tenancy and aggressive horizontal scaling.