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Databases · head to head

NATS vs OpenSearch

NATS logo

NATS

Databases

High-performance messaging system for cloud-native applications

From
Free
Rated
-
Full reviewWebsite
OpenSearch logo

OpenSearch

Databases

Open-source search and analytics suite forked from Elasticsearch

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: NATS core NATS has no persistence at all, so messages are lost if no subscriber is listening; OpenSearch diverged from Elasticsearch since 7.10, so clients, plugins and features no longer map one to one
  • They diverge on capability: NATS covers Very low latency, OpenSearch covers Full-text search.

Where they differ

Only the attributes on which NATS and OpenSearch actually diverge.

Attributes where NATS and OpenSearch differ
AttributeNATSOpenSearch
Pricing modelOpen source, no licence feeOpen source, no licence fee; managed services billed separately
PlatformsLinux, macOS, Windows, Docker, KubernetesLinux, Docker, Kubernetes, Self-hosted

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

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 NATS

  • Very low latency
  • JetStream
  • Single binary
  • Request-reply

Only in OpenSearch

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

What people use each for

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

NATS

  • Service-to-service messaging where latency is the binding constraintnot OpenSearch
  • Edge and IoT messaging where a lightweight broker mattersnot OpenSearch
  • Replacing a heavier broker when the workload does not need its guaranteesnot OpenSearch

OpenSearch

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

Where each one falls short

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

NATS

  • Core NATS has no persistence at all, so messages are lost if no subscriber is listening
  • JetStream adds the durability but also the operational complexity NATS is chosen to avoid
  • A much smaller ecosystem than Kafka or RabbitMQ, with fewer connectors and integrations
  • Fewer people know it, so hiring and existing organisational knowledge favour the alternatives

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

Pricing, plan by plan

NATS

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

OpenSearch

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

Which should you pick?

Choose NATS if

  • You need very low latency.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker, Kubernetes.
  • You also want jetstream.
NATS review

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

Questions people ask

Is NATS or OpenSearch better?
Neither clearly leads. NATS starts at Free and OpenSearch at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, NATS or OpenSearch?
NATS starts at Free and OpenSearch at Free.
Does NATS or OpenSearch run on more platforms?
NATS runs on Linux, macOS, Windows, Docker, Kubernetes. OpenSearch runs on Linux, Docker, Kubernetes, Self-hosted.
Can I use NATS for free?
Both have a free tier, so you can try either at no cost before committing.
What is NATS best used for?
NATS is most often used for service-to-service messaging where latency is the binding constraint, edge and iot messaging where a lightweight broker matters, replacing a heavier broker when the workload does not need its guarantees. Of those, service-to-service messaging where latency is the binding constraint and edge and iot messaging where a lightweight broker matters are not what OpenSearch is typically brought in for.
What can NATS do that OpenSearch cannot?
NATS covers Very low latency, JetStream, Single binary, Request-reply. OpenSearch covers Full-text search, OpenSearch Dashboards, Log analytics, Vector search.

Answered from the vendors’ own pages

NATS: Is NATS free?

Yes, open source and CNCF-graduated. Synadia sells a managed service.

OpenSearch: Is OpenSearch free?

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

NATS: Does NATS persist messages?

Core NATS does not — it is fire-and-forget. JetStream adds persistence, streaming and replay when you need them.

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.

NATS: NATS or Kafka?

NATS is far lighter and lower latency, and much simpler to run. Kafka is the answer when you need a durable replayable log and a large connector ecosystem.

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.

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