Apache Pulsar

A distributed message broker for pub-sub and queue-based messaging at scale

Also known as
apache-pulsar

What is Apache Pulsar?

A message broker supporting both pub-sub and queue-based messaging patterns. It provides durable storage with strong ordering guarantees, horizontally scales to millions of topics and messages per second, and supports geo-replication for distributed deployments.

Independently observed

Apache Pulsar pricing

We don't have Apache Pulsar's full plan breakdown yet (its pricing page resisted automated reading). Here's what we could confirm. Always check live pricing for exact numbers.

What Apache Pulsar does

The capabilities that matter for message queues, normalised so it lines up with every alternative. “-” means we haven't confirmed it, not that it's missing.

Core
Messaging paradigm
Pub/sub
Correctness
Delivery guarantee
Exactly-once
Ordering guarantee
Per-partition
Durability
Durable replayable log
Message replay / rewind
Interop
Wire protocol
pulsar://
Kafka-protocol compatible
Scale
Partitioned horizontal scaling
Geo / cross-region replication
Consumption
Consumer groups / competing consumers
Dead-letter queue
-
Deployment
Managed cloud offering exists
-
Hosting
Cloud + self-hosted
Processing
Built-in stream processing
Independently observed

Platform & deployment

Independently observed
Platforms
  • CLI
  • macOS
  • Linux
  • Windows
Deployment
  • Self-hosted

Integrations (30)

Independently observed
  • Kafka
  • RabbitMQ
  • MongoDB
  • Cassandra
  • Elasticsearch
  • HBase
  • HDFS
  • InfluxDB
  • Redis
  • Solr
  • DynamoDB
  • Kinesis
  • Azure Data Explorer
  • ClickHouse
  • PostgreSQL
  • MariaDB
  • SQLite
  • Debezium MySQL
  • Debezium PostgreSQL
  • Debezium MongoDB
  • Debezium Oracle
  • Debezium Microsoft SQL Server
  • Canal
  • Aerospike
  • Alluxio
  • NSQ
  • Netty
  • HTTP
  • File
  • Kafka Connect Adaptor

Security & compliance

Known vulnerabilities: 1 (0 in the last 12 months), max severity MODERATE sourcea count reflects scale & disclosure, not quality

Apache Pulsar FAQ

Common questions about Apache Pulsar, answered from independent, dated evidence.

What is Apache Pulsar?

A distributed messaging system built for cloud deployments that enables applications to reliably publish and consume messages—either individually or as continuous streams—with sub-10-millisecond latency, supporting millions of independent topics and large-scale streaming workloads. It is indexed under Message Queues.

Source: https://pulsar.apache.org

Is Apache Pulsar free to use?

Apache Pulsar is open source, so it can be self-hosted and used at no licence cost. It is released under the Apache-2.0 licence. Pricing changes often, so verify at source before relying on it.

Source: https://pulsar.apache.org

What platforms does Apache Pulsar support?

Apache Pulsar supports a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.

Source: https://pulsar.apache.org

Can Apache Pulsar be self-hosted?

Yes. Apache Pulsar can be deployed cloud / SaaS and self-hosted, so it does not have to run on the vendor's infrastructure.

Source: https://pulsar.apache.org

What does Apache Pulsar integrate with?

We have confirmed 27 integrations for Apache Pulsar, including Kafka, RabbitMQ, MongoDB, Cassandra, Elasticsearch, HBase, HDFS and InfluxDB, plus 19 more. This is what we could verify from public sources, so the vendor may support others we have not indexed.

Source: https://pulsar.apache.org

Is Apache Pulsar open source?

Yes. Apache Pulsar is published under the Apache-2.0 licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.

Source: https://github.com/apache/pulsar

Apache Pulsar alternatives

Other message queues we track, ranked by the same independent score.

All Apache Pulsar alternatives, ranked →

Compare Apache Pulsar

Side by side against other message queues, attribute by attribute, with a source on every value.

Independent · unbought · dated

The vioscaleAI score: one lens on the evidence

Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for Apache Pulsar, not the verdict.

Balanced composite 57 / 100
low · 32%
Signal contributions to the composite score
SignalScoreWeightContributionEvidence
Development activity630.095.9
Capabilities870.065.5
Integrations450.073.3
Dependent projects500.063.1
Security score710.043.0
Stars790.032.1
Release cadence00.050.0-
Security posture00.120.0-
Package downloads00.140.0-
Developer Q&A activity00.060.0-

Computed . Re-weight it by intent, or see the full method.

All data & sourcesshow ↓

Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.

Activity

AttributeValueEvidence
Commits last 30d100mediumsource · 2026-09-10 · 65%

Adoption

AttributeValueEvidence
Github stars15,328highsource · 2026-09-10 · 90%
Dependent repos982highsource · 2026-09-10 · 85%

Content

AttributeValueEvidence
Faq6 itemsmediumsource · 2026-09-10 · 66%

Features

AttributeValueEvidence
CapabilitiesHosting: both · Ordering: per_partition · Paradigm: pubsub · Protocol: pulsar:// · Message replay: Yes · Persistent log: Yesmediumsource · 2026-09-14 · 60%

Integrations

AttributeValueEvidence
Count35mediumsource · 2026-08-14 · 60%

Language

AttributeValueEvidence
PrimaryJavahighsource · 2026-09-10 · 90%

License

AttributeValueEvidence
SpdxApache-2.0highsource · 2026-09-10 · 95%

Pricing

AttributeValueEvidence
Modelopen_sourcemediumsource · 2026-09-14 · 60%
Price levelfreemediumsource · 2026-09-14 · 60%
Free tierYesmediumsource · 2026-09-14 · 60%

Release

AttributeValueEvidence
History20 itemsmediumsource · 2026-09-10 · 70%

Security

AttributeValueEvidence
Scorecard7.1highsource · 2026-09-10 · 90%
VulnerabilitiesCount: 1 · Source: https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=maven&package_name=org.apache.pulsar%3Apulsar-client&per_page=100 · Last 12m: 0 · Max severity: MODERATEhighsource · 2026-09-10 · 90%
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