M3DB vs Thanos

M3DB: Uber-born distributed TSDB and aggregator for Prometheus-scale metrics with tunable replication. 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 m3db for

+Very large Prometheus remote-write backends
+Migrating Graphite at scale to PromQL
+Multi-resolution metrics retention

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

M3DBUber-born distributed TSDB and aggregator for Prometheus-scale metrics with tunable replication.

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

M3 project (Uber, Chronosphere)

Thanos community (CNCF)

First release

2018

Latest version

1.6.0 (Sep 25, 2026)

0.42.4 (Jul 30, 2026)

License

Open source (permissive)Apache License 2.0

Free tier

✓

popularity

WhichDB Score

4.2

13.1

Rank

#416

#257

GitHub stars

4.9K

14.3K

Stack Overflow questions

–

scale & guarantees

Comfortable data size

Massive (Multi-PB)

Horizontal scaling

Native

Multi-region

None

ACID

None

Consistency

Tunable

Eventual

Schema

Schemaless

Architecture

Distributed, Client server

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, Graphite, M3QL

PromQL

Client languages

–

Best for

Observability, Time-series

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

M3DB vs Thanos: FAQ

What is the difference between M3DB and Thanos?

M3DB: Uber-born distributed TSDB and aggregator for Prometheus-scale metrics with tunable replication. Thanos: Sidecar-plus-object-storage layer giving Prometheus global queries, HA dedup and long retention.

When should I choose M3DB over Thanos?

Choose M3DB for very large Prometheus remote-write backends, migrating Graphite at scale to PromQL and multi-resolution metrics retention. Choose Thanos for long-term storage for multi-cluster Prometheus, global dashboards across regions and cost-efficient metrics retention on S3/GCS.

Is M3DB or Thanos more popular?

Thanos ranks #257 on the WhichDB Score (13.1/100) and M3DB ranks #416 (4.2/100). Popularity is not fit: check the requirements that matter for your project.

Are M3DB and Thanos open source?

Yes. M3DB is open source. License: Apache License 2.0. Yes. Thanos is open source. License: Apache License 2.0.