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Databases · head to head

OpenSearch vs Thanos

OpenSearch logo

OpenSearch

Databases

Open-source search and analytics suite forked from Elasticsearch

From
Free
Rated
-
Full reviewWebsite
Thanos logo

Thanos

Cloud

Highly available Prometheus with long-term object storage

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: OpenSearch diverged from Elasticsearch since 7.10, so clients, plugins and features no longer map one to one; Thanos several components — sidecar, store, querier, compactor, ruler — each with its own configuration and failure modes
  • They diverge on capability: OpenSearch covers Full-text search, Thanos covers Global query.
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which OpenSearch and Thanos actually diverge.

Attributes where OpenSearch and Thanos differ
AttributeOpenSearchThanos
Pricing modelOpen source, no licence fee; managed services billed separatelyOpen source, no licence fee
PlatformsLinux, Docker, Kubernetes, Self-hostedKubernetes, Linux, Docker
CategoryDatabasesCloud

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in OpenSearch

  • Full-text search
  • OpenSearch Dashboards
  • Log analytics
  • Vector search

Only in Thanos

  • Global query
  • Object storage retention
  • Deduplication
  • Downsampling

What people use each for

The jobs each tool is most often brought in to do.

OpenSearch

  • Log and observability storage where an Apache-2.0 licence is a requirementnot Thanos
  • Replacing Elasticsearch after the licence change without changing architecturenot Thanos
  • Search plus analytics on one cluster rather than two systemsnot Thanos

Thanos

  • Querying metrics across many clusters or regions from one placenot OpenSearch
  • Retaining metrics for years without local disk growthnot OpenSearch
  • Removing the gap that appears when a single Prometheus instance restartsnot OpenSearch

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

OpenSearch

  • Diverged from Elasticsearch since 7.10, so clients, plugins and features no longer map one to one
  • Operationally heavy in the way Elasticsearch is: cluster sizing, shard strategy and JVM tuning are ongoing work
  • Smaller ecosystem of third-party tooling than Elasticsearch, which most integrations still target first
  • Overkill for plain application search, where a dedicated search engine is far simpler

Thanos

  • Several components — sidecar, store, querier, compactor, ruler — each with its own configuration and failure modes
  • The compactor is a common source of operational trouble and must not run twice against the same bucket
  • Query latency over object storage is meaningfully higher than local Prometheus
  • Object storage costs and API request charges become real at high volume

Pricing, plan by plan

OpenSearch

Free
  • OpenSearchFree
    • Full functionality
    • Self-hosted
    • No usage limits

Thanos

Free
  • ThanosFree
    • Full functionality
    • No usage limits
    • Community support

Which should you pick?

Choose OpenSearch if

  • You need full-text search.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want opensearch dashboards.
OpenSearch review

Choose Thanos if

  • You need global query.
  • You want to start without paying.
  • You work on Kubernetes, Linux, Docker.
  • You also want object storage retention.
Thanos review

Questions people ask

Is OpenSearch or Thanos better?
Neither clearly leads. OpenSearch starts at Free and Thanos at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, OpenSearch or Thanos?
OpenSearch starts at Free and Thanos at Free.
Does OpenSearch or Thanos run on more platforms?
OpenSearch runs on Linux, Docker, Kubernetes, Self-hosted. Thanos runs on Kubernetes, Linux, Docker.
Can I use OpenSearch for free?
Both have a free tier, so you can try either at no cost before committing.
What is OpenSearch best used for?
OpenSearch is most often used for log and observability storage where an apache-2.0 licence is a requirement, replacing elasticsearch after the licence change without changing architecture, search plus analytics on one cluster rather than two systems. Of those, log and observability storage where an apache-2.0 licence is a requirement and replacing elasticsearch after the licence change without changing architecture are not what Thanos is typically brought in for.
What can OpenSearch do that Thanos cannot?
OpenSearch covers Full-text search, OpenSearch Dashboards, Log analytics, Vector search. Thanos covers Global query, Object storage retention, Deduplication, Downsampling.

Answered from the vendors’ own pages

OpenSearch: Is OpenSearch free?

Yes, Apache 2.0 licensed under the Linux Foundation. Amazon OpenSearch Service is a paid managed option.

Thanos: Is Thanos free?

Yes, open source and CNCF-incubating. Costs are the object storage it uses.

OpenSearch: Why does OpenSearch exist?

Elastic moved Elasticsearch off the Apache 2.0 licence in 2021. AWS forked the last Apache-licensed version, and the project now sits under the Linux Foundation.

Thanos: Does Thanos replace Prometheus?

No. It runs alongside existing Prometheus servers, adding global query, deduplication and long-term storage.

OpenSearch: Is OpenSearch compatible with Elasticsearch?

It was at the 7.10 fork point. Both have developed independently since, so compatibility weakens with every release and should be verified for the features you use.

Thanos: Thanos or VictoriaMetrics?

Thanos layers onto Prometheus using object storage and is the more established multi-cluster answer. VictoriaMetrics is a separate store aiming at lower resource use and fewer moving parts.

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