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Databases · head to head

Apache Kafka vs Elasticsearch

Apache Kafka logo

Apache Kafka

Databases

Open-source distributed event streaming platform

From
Free
Rated
-
Full reviewWebsite
Elasticsearch logo

Elasticsearch

Databases

The heart of the Elastic Stack for search and analytics

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Apache Kafka operationally heavy to self-host: brokers, storage, rebalancing and upgrades are a standing job, which is why managed Kafka is a large market; Elasticsearch eventual consistency model with 1-second default refresh interval, not suitable for real-time transactional requirements
  • They diverge on capability: Apache Kafka covers Durable commit log, Elasticsearch covers Full-text Search.

Where they differ

Only the attributes on which Apache Kafka and Elasticsearch actually diverge.

Attributes where Apache Kafka and Elasticsearch differ
AttributeApache KafkaElasticsearch
Pricing modelOpen source, no licence fee; managed services billed separatelyUnknown
PlatformsLinux, Windows, macOS, Self-hosted, DockerLinux, Windows, macOS, Docker, Kubernetes
FoundedUnknown2010

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 Apache Kafka

  • Durable commit log
  • Horizontal scale
  • Kafka Connect
  • Kafka Streams
  • Replication
  • Low latency

Only in Elasticsearch

  • Full-text Search
  • Real-time Analytics
  • Distributed Architecture
  • RESTful API
  • Schema-free JSON
  • Aggregations
  • Machine Learning
  • Kibana

What people use each for

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

Apache Kafka

  • Moving events between services without point-to-point couplingnot Elasticsearch
  • Feeding analytics and warehouses from operational systems in near real timenot Elasticsearch
  • Replaying history to rebuild state after a consumer bugnot Elasticsearch
  • Buffering bursty producers ahead of slower downstream systemsnot Elasticsearch

Elasticsearch

  • Real-time applicationsnot Apache Kafka
  • Content managementnot Apache Kafka
  • User profilesnot Apache Kafka
  • Mobile backendsnot Apache Kafka
  • Cachingnot Apache Kafka

Where each one falls short

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

Apache Kafka

  • Operationally heavy to self-host: brokers, storage, rebalancing and upgrades are a standing job, which is why managed Kafka is a large market
  • Overkill for straightforward job queues, where a simpler broker is easier to run and reason about
  • Ordering guarantees hold per partition, not per topic, and getting partitioning wrong is a common and expensive design mistake
  • The ecosystem is fragmented across the Apache project and vendor distributions, so documentation and tooling advice often assume a particular distribution

Elasticsearch

  • Eventual consistency model with 1-second default refresh interval, not suitable for real-time transactional requirements
  • No support for ACID transactions or rollbacks; updates delete and re-insert documents
  • JVM-dependent architecture requires careful memory management and monitoring to prevent garbage collection issues at scale

Pricing, plan by plan

Apache Kafka

Free
  • Apache KafkaFree
    • Full platform
    • Kafka Connect
    • Kafka Streams

Elasticsearch

Free
  • Self-ManagedFree
    • Open source
    • Self-hosted
  • Elasticsearch Cloud$16.4/month
    • Managed service
    • 14-day free trial

Which should you pick?

Choose Apache Kafka if

  • You need durable commit log.
  • You want to start without paying.
  • You work on Linux, Windows, macOS, Self-hosted, Docker.
  • You also want horizontal scale.
Apache Kafka review

Choose Elasticsearch if

  • You need full-text search.
  • You want to start without paying.
  • You work on Linux, Windows, macOS, Docker, Kubernetes.
  • You also want real-time analytics.
Elasticsearch review

Questions people ask

Is Apache Kafka or Elasticsearch better?
Neither clearly leads. Apache Kafka starts at Free and Elasticsearch at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Apache Kafka or Elasticsearch?
Apache Kafka starts at Free and Elasticsearch at Free.
Does Apache Kafka or Elasticsearch run on more platforms?
Apache Kafka runs on Linux, Windows, macOS, Self-hosted, Docker. Elasticsearch runs on Linux, Windows, macOS, Docker, Kubernetes.
Can I use Apache Kafka for free?
Both have a free tier, so you can try either at no cost before committing.
What is Apache Kafka best used for?
Apache Kafka is most often used for moving events between services without point-to-point coupling, feeding analytics and warehouses from operational systems in near real time, replaying history to rebuild state after a consumer bug, buffering bursty producers ahead of slower downstream systems. Of those, moving events between services without point-to-point coupling and feeding analytics and warehouses from operational systems in near real time are not what Elasticsearch is typically brought in for.
What can Apache Kafka do that Elasticsearch cannot?
Apache Kafka covers Durable commit log, Horizontal scale, Kafka Connect, Kafka Streams. Elasticsearch covers Full-text Search, Real-time Analytics, Distributed Architecture, RESTful API.

Answered from the vendors’ own pages

Apache Kafka: Is Apache Kafka free?

Yes. Kafka is open source under the Apache License v2 with no licence fee. Costs come from the infrastructure you run it on, or from a managed service such as Confluent Cloud.

Elasticsearch: Is Elasticsearch free?

Yes, Elasticsearch can be deployed as free and open-source software for self-managed installations. Elastic Cloud managed service starts at $16.40 per month, with a free 14-day trial available.

Source
Apache Kafka: How is Kafka different from a message queue?

A queue usually removes a message once it is consumed. Kafka keeps an ordered, durable log, so consumers track their own position and history can be replayed — which is what makes rebuilding state after a bug possible.

Elasticsearch: Can I use Elasticsearch without Kibana?

Yes, Elasticsearch is a search engine independent of Kibana. Kibana is a visualization and analytics tool that works with Elasticsearch but is optional. You can use the Elasticsearch API directly for searching.

Source
Apache Kafka: Who uses Kafka?

The project reports use by more than 80% of the Fortune 100, with over 5 million lifetime downloads.

Elasticsearch: Does Elasticsearch support real-time indexing?

Elasticsearch indexes data with a refresh interval, typically 1 second. Data becomes searchable after the refresh cycle, making it near-real-time but not instantaneous. This can be configured but impacts performance.

Source
Apache Kafka: Do I need to run Kafka myself?

No. Self-hosting is the operationally expensive option; managed services such as Confluent Cloud run the brokers for you and bill on throughput and storage instead.

Elasticsearch: What are Elasticsearch's scaling limitations?

Elasticsearch requires careful operational management at scale, including shard balancing, heap sizing, and monitoring. Large clusters can suffer from garbage collection issues and become expensive to operate.

Source
Elasticsearch: Does Elasticsearch support transactions and rollbacks?

No, Elasticsearch does not support ACID transactions or rollbacks. Updates are expensive operations that delete and re-insert documents, making it unsuitable for transactional workloads.

Source
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