# Apache Pulsar vs Google Cloud Pub/Sub

**Leader by vioscaleAI score:** Apache Pulsar

| Attribute | Apache Pulsar | Google Cloud Pub/Sub |
|---|---|---|
| **vioscaleAI score** | 60.2 (38% (low)) | 53.7 (50% (medium)) |
| activity.commits_last_30d | 100 | - |
| adoption.dependent_repos | 316 | - |
| adoption.github_stars | 15,343 | - |
| content.faq | `[{"answer":"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","question":"What is Apache Pulsar?","confidence":0.6},{"answer":"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","question":"Is Apache Pulsar free to use?","confidence":0.6},{"answer":"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","question":"What platforms does Apache Pulsar support?","confidence":0.6},{"answer":"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","question":"Can Apache Pulsar be self-hosted?","confidence":0.6},{"answer":"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","question":"What does Apache Pulsar integrate with?","confidence":0.6},{"answer":"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","question":"Is Apache Pulsar open source?","confidence":0.95}]` | `[{"answer":"Google Cloud's managed messaging system that reliably routes messages between applications with support for real-time data processing and integration with analytics, log management, and data platforms. It is indexed under Message Queues.","source":"https://cloud.google.com/pubsub","question":"What is Google Cloud Pub/Sub?","confidence":0.6},{"answer":"Google Cloud Pub/Sub offers a free tier, so you can start without paying. Paid plans start at $0.27. Pricing changes often, so verify at source before relying on it.","source":"https://cloud.google.com/pubsub","question":"Is Google Cloud Pub/Sub free?","confidence":0.6},{"answer":"We have confirmed browser-based access to Google Cloud Pub/Sub. That is the extent of what we could verify from public sources, so it may well offer desktop or mobile clients we have not indexed.","source":"https://cloud.google.com/pubsub","question":"What platforms does Google Cloud Pub/Sub support?","confidence":0.6},{"answer":"Not fully, on what we have confirmed. Google Cloud Pub/Sub is offered as cloud / SaaS and hybrid, and a hybrid deployment usually means some components can run on your own infrastructure while the rest stays vendor-hosted. We have not confirmed a completely self-hosted option, so check with the vendor if that is a requirement.","source":"https://cloud.google.com/pubsub","question":"Can Google Cloud Pub/Sub be self-hosted?","confidence":0.6},{"answer":"We have confirmed 11 integrations for Google Cloud Pub/Sub, including BigQuery, Cloud Storage, Dataflow, Splunk, Datadog, Striim, Informatica and Confluent Cloud, plus 3 more. This is what we could verify from public sources, so the vendor may support others we have not indexed.","source":"https://cloud.google.com/pubsub","question":"What does Google Cloud Pub/Sub integrate with?","confidence":0.6},{"answer":"Google Cloud Pub/Sub is available worldwide. Its primary market is the United States.","source":"https://cloud.google.com/pubsub","question":"Where is Google Cloud Pub/Sub available?","confidence":0.5}]` |
| deployment.options | `{"cloud":true,"self_hosted":true}` | `{"cloud":true,"hybrid":true}` |
| description.long | 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. | Google Cloud's publish-subscribe messaging platform that delivers events to multiple subscribers with at-least-once delivery guarantees, cross-zone replication, and optional per-key ordering. It integrates with popular data processing, analytics, and monitoring tools for end-to-end data streaming solutions. |
| features.capabilities | `{"hosting":"both","ordering":"per_partition","paradigm":"pubsub","protocol":"pulsar://","message_replay":true,"persistent_log":true,"consumer_groups":true,"geo_replication":true,"kafka_compatible":true,"stream_processing":true,"delivery_guarantee":"exactly_once","horizontal_scaling":true}` | `{"hosting":"cloud","ordering":"per_key","paradigm":"pubsub","message_replay":true,"persistent_log":true,"consumer_groups":true,"geo_replication":true,"managed_offering":true,"stream_processing":true,"delivery_guarantee":"at_least_once","horizontal_scaling":true}` |
| integrations.count | 35 | 9 |
| integrations.list | `[{"name":"Kafka"},{"name":"RabbitMQ"},{"name":"MongoDB"},{"name":"Cassandra"},{"name":"Elasticsearch"},{"name":"HBase"},{"name":"HDFS"},{"name":"InfluxDB"},{"name":"Redis"},{"name":"Solr"},{"name":"DynamoDB"},{"name":"Kinesis"},{"name":"Azure Data Explorer"},{"name":"ClickHouse"},{"name":"PostgreSQL"},{"name":"MariaDB"},{"name":"SQLite"},{"name":"Debezium MySQL"},{"name":"Debezium PostgreSQL"},{"name":"Debezium MongoDB"},{"name":"Debezium Oracle"},{"name":"Debezium Microsoft SQL Server"},{"name":"Canal"},{"name":"Aerospike"},{"name":"Alluxio"},{"name":"NSQ"},{"name":"Netty"},{"name":"HTTP"},{"name":"File"},{"name":"Kafka Connect Adaptor","native":true,"direction":"bidirectional"},{"name":"MySQL","native":true}]` | `[{"name":"BigQuery"},{"name":"Cloud Storage"},{"name":"Dataflow"},{"name":"Splunk","category":"logs"},{"name":"Datadog","category":"logs"},{"name":"Striim","category":"data integration"},{"name":"Informatica","category":"data integration"},{"name":"Confluent Cloud"},{"name":"Apache Kafka"},{"name":"Knative Eventing","category":"serverless"},{"name":"Looker Studio","category":"visualization"},{"name":"Data Studio","category":"visualization"}]` |
| language.primary | Java | - |
| license.spdx | Apache-2.0 | - |
| market.availability | - | `{"primaryMarkets":["US"],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` |
| platform.support | `{"cli":true,"mac":true,"web":true,"linux":true,"windows":true}` | `{"web":true}` |
| pricing | `{"type":"open_source","sourceUrl":"https://pulsar.apache.org","retrievedAt":"2026-10-14T22:35:49.214Z"}` | `{"type":"usage","plans":[{"free":false,"name":"Standard Pub/Sub","summary":"$40/TiB throughput + $0.27/GiB-month storage (first 10 GiB throughput free)","features":["At-least-once message delivery","Per-key message ordering","Pull and push delivery modes","Cross-zone replication","Automatic scaling and provisioning","Message retention and snapshots"],"components":[{"per":{"qty":1,"unit":"TiB"},"kind":"metered","amount":40,"currency":"USD"},{"per":{"qty":1,"unit":"GiB-month"},"kind":"metered","amount":0.27,"currency":"USD"}],"description":"Pay-as-you-go pricing based on message throughput and retention","contactSales":false,"includedLimits":{"free_throughput":"10 GiB/month"}}],"addOns":[{"name":"BigQuery Subscription","components":[{"per":{"qty":1,"unit":"TiB"},"kind":"metered","amount":50,"currency":"USD"}]},{"name":"Cloud Storage Subscription","components":[{"per":{"qty":1,"unit":"TiB"},"kind":"metered","amount":50,"currency":"USD"}]},{"name":"Kinesis Data Streams Import","components":[{"per":{"qty":1,"unit":"TiB"},"kind":"metered","amount":50,"currency":"USD"}]},{"name":"Other Source Imports (Azure Event Hubs, AWS MSK, Confluent Cloud)","components":[{"per":{"qty":1,"unit":"TiB"},"kind":"metered","amount":80,"currency":"USD"}]}],"summary":"Usage-based: $40/TiB throughput, $0.27/GiB-month storage. Free tier: 10 GiB/month throughput.","currency":"USD","freeTier":true,"sourceUrl":"https://cloud.google.com/pubsub","retrievedAt":"2026-08-05T13:22:58.268Z","startingPrice":{"amount":0.27,"period":"month","currency":"USD"},"billingPeriods":["month"]}` |
| pricing.free_tier | yes | yes |
| pricing.model | open_source | freemium |
| pricing.price_level | free | low |
| pricing.transparent | - | no |
| release.cadence_days | 3 | - |
| release.history | `[{"url":"https://github.com/apache/pulsar/releases/tag/v5.0.0","date":"2026-10-05T19:22:24Z","type":"stable","version":"v5.0.0"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.2.5","date":"2026-10-05T19:23:03Z","type":"stable","version":"v4.2.5"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.0.14","date":"2026-10-05T19:23:29Z","type":"stable","version":"v4.0.14"},{"url":"https://github.com/apache/pulsar/releases/tag/v5.0.0-M2","date":"2026-09-16T23:33:14Z","type":"prerelease","version":"v5.0.0-M2"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.2.4","date":"2026-08-03T09:19:30Z","type":"stable","version":"v4.2.4"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.0.13","date":"2026-08-03T09:19:06Z","type":"stable","version":"v4.0.13"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.2.3","date":"2026-07-06T08:46:50Z","type":"stable","version":"v4.2.3"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.0.12","date":"2026-07-06T08:46:18Z","type":"stable","version":"v4.0.12"},{"url":"https://github.com/apache/pulsar/releases/tag/v5.0.0-M1","date":"2026-06-23T14:11:26Z","type":"prerelease","version":"v5.0.0-M1"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.2.2","date":"2026-06-08T18:16:45Z","type":"stable","version":"v4.2.2"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.0.11","date":"2026-06-08T18:16:01Z","type":"stable","version":"v4.0.11"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.2.1","date":"2026-04-27T13:04:33Z","type":"stable","version":"v4.2.1"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.0.10","date":"2026-04-27T13:04:17Z","type":"stable","version":"v4.0.10"},{"url":"https://github.com/apache/pulsar/releases/tag/v3.0.17","date":"2026-04-27T13:03:58Z","type":"stable","version":"v3.0.17"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.2.0","date":"2026-03-31T21:12:26Z","type":"stable","version":"v4.2.0"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.1.3","date":"2026-02-19T19:48:49Z","type":"stable","version":"v4.1.3"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.0.9","date":"2026-02-19T19:48:13Z","type":"stable","version":"v4.0.9"},{"url":"https://github.com/apache/pulsar/releases/tag/v3.0.16","date":"2026-02-16T09:24:53Z","type":"stable","version":"v3.0.16"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.1.2","date":"2025-11-17T07:58:34Z","type":"stable","version":"v4.1.2"},{"url":"https://github.com/apache/pulsar/releases/tag/v4.0.8","date":"2025-11-17T07:58:06Z","type":"stable","version":"v4.0.8"}]` | - |
| reliability.status_page | - | yes |
| security.scorecard | 7.1 | - |
| security.trust_center | https://pulsar.apache.org/docs/5.0.x/security-athenz/ | - |
| security.vulnerabilities | `{"count":0,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=maven&package_name=org.apache.pulsar%3Apulsar-client-admin&per_page=100","last_12m":0,"max_severity":null}` | - |

## Capabilities (Message Queues)

| Capability | Apache Pulsar | Google Cloud Pub/Sub |
|---|:--:|:--:|
| **Core** |  |  |
| Messaging paradigm | Pub/sub | Pub/sub |
| **Correctness** |  |  |
| Delivery guarantee | Exactly-once | At-least-once |
| Ordering guarantee | Per-partition | Per-key |
| **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 | Cloud only |
| **Processing** |  |  |
| Built-in stream processing | ✓ | ✓ |

*Source: vioscaleAI. Generated 2026-10-16T20:04:06.640Z. "-" = undocumented, not absent.*
