Cortex vs Thanos

Cortex: CNCF multi-tenant, horizontally scalable long-term storage for Prometheus metrics on object storage. Thanos: Sidecar-plus-object-storage layer giving Prometheus global queries, HA dedup and long retention.

key differences

These two are very similar on paper. Compare ecosystems, pricing and team familiarity.

choose cortex for

+Internal metrics-as-a-service for many teams
+Long-term Prometheus storage on object storage
+Multi-tenant SaaS monitoring backends

best at · Observability, Time-series

choose thanos for

+Long-term storage for multi-cluster Prometheus
+Global dashboards across regions
+Cost-efficient metrics retention on S3/GCS

best at · Observability, Time-series

CortexCNCF multi-tenant, horizontally scalable long-term storage for Prometheus metrics on object storage.

ThanosSidecar-plus-object-storage layer giving Prometheus global queries, HA dedup and long retention.

overview

Primary model

Time-Series

Also supports

–

Type

Database engine

Status

Active

Developer

Cortex community (CNCF)

Thanos community (CNCF)

First release

2016

2018

Latest version

1.21.1 (Jun 5, 2026)

0.42.4 (Jul 30, 2026)

License

Open source (permissive)Apache License 2.0

Free tier

✓

popularity

WhichDB Score

7.2

13.1

Rank

#347

#257

GitHub stars

5.9K

14.3K

Stack Overflow questions

–

scale & guarantees

Comfortable data size

Massive (Multi-PB)

Horizontal scaling

Native

Multi-region

None

ACID

None

Consistency

Eventual

Schema

Schemaless

Architecture

Distributed, Shared storage

deployment

Self-hosted

✓

Vendor-managed cloud

—

Serverless

—

Embedded

—

Edge

—

Clouds

–

capabilities

Transactions

—

Joins

—

Secondary indexes

—

Full-text search

—

Vector search

—

Geospatial

—

JSON

—

Change data capture

—

Triggers

—

Stored procedures

—

Materialized views

—

TTL / expiry

✓

Pub/Sub

—

Columnar storage

—

In-memory

—

Durable persistence

✓

Compression

✓

Encryption at rest

—

Role-based access

—

Time travel

—

Branching

—

Online schema changes

—

Streaming ingest

✓

Offline sync

—

Runs in WebAssembly

—

interfaces

Query languages

PromQL

Client languages

–

Best for

Observability, Time-series

Add more to this comparison Not sure either fits? Try smart match

Cortex vs Thanos: FAQ

What is the difference between Cortex and Thanos?

Cortex: CNCF multi-tenant, horizontally scalable long-term storage for Prometheus metrics on object storage. Thanos: Sidecar-plus-object-storage layer giving Prometheus global queries, HA dedup and long retention.

When should I choose Cortex over Thanos?

Choose Cortex for internal metrics-as-a-service for many teams, long-term Prometheus storage on object storage and multi-tenant SaaS monitoring backends. Choose Thanos for long-term storage for multi-cluster Prometheus, global dashboards across regions and cost-efficient metrics retention on S3/GCS.

Is Cortex or Thanos more popular?

Thanos ranks #257 on the WhichDB Score (13.1/100) and Cortex ranks #347 (7.2/100). Popularity is not fit: check the requirements that matter for your project.

Are Cortex and Thanos open source?

Yes. Cortex is open source. License: Apache License 2.0. Yes. Thanos is open source. License: Apache License 2.0.