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Databases · head to head

Apache Pulsar vs Firestore

Apache Pulsar logo

Apache Pulsar

Databases

Cloud-native messaging and streaming with separated storage

From
Free
Rated
-
Full reviewWebsite
Firestore logo

Firestore

Databases

Flexible, scalable NoSQL cloud database from Firebase

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Apache Pulsar more components than Kafka: brokers, BookKeeper and ZooKeeper each need operating; Firestore the no-cost Spark plan caps Standard edition at 50,000 document reads, 20,000 writes and 20,000 deletes per day
  • They diverge on capability: Apache Pulsar covers Separated storage, Firestore covers Document Model.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Apache Pulsar and Firestore actually diverge.

Attributes where Apache Pulsar and Firestore differ
AttributeApache PulsarFirestore
Pricing modelOpen source, no licence feefreemium
PlatformsLinux, Docker, Kubernetes, Self-hostedWeb, Ios, Android, Flutter
FoundedUnknown2011

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 Pulsar

  • Separated storage
  • Queuing and streaming
  • Built-in multi-tenancy
  • Geo-replication

Only in Firestore

  • Document Model
  • Real-time Updates
  • Offline Support
  • ACID Transactions
  • Expressive Queries
  • Multi-region
  • Security Rules
  • Firebase Auth

What people use each for

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

Apache Pulsar

  • Platforms needing both work queues and replayable streams without running two systemsnot Firestore
  • Multi-tenant messaging where isolation between teams is a requirementnot Firestore
  • Deployments where storage and traffic grow at genuinely different ratesnot Firestore

Firestore

  • Storing structured application data with realtime listenersnot Apache Pulsar
  • Backing mobile and web apps with a serverless document databasenot Apache Pulsar
  • Building offline first apps that sync when connectivity returnsnot Apache Pulsar

Where each one falls short

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

Apache Pulsar

  • More components than Kafka: brokers, BookKeeper and ZooKeeper each need operating
  • Correspondingly harder to run well, and the expertise is rarer than Kafka expertise
  • A much smaller ecosystem of connectors, tooling and hiring pool than Kafka
  • The architectural advantages only pay off at a scale most deployments never reach

Firestore

  • The no-cost Spark plan caps Standard edition at 50,000 document reads, 20,000 writes and 20,000 deletes per day
  • The Spark plan caps storage at 1 GiB and network egress at 10 GiB per month
  • Charging is per document read, so a query returning many documents bills for every one of them
  • Going beyond the free thresholds requires the pay as you go Blaze plan billed at Google Cloud rates with no fixed monthly ceiling

Pricing, plan by plan

Apache Pulsar

Free
  • Apache PulsarFree
    • Full functionality
    • No usage limits
    • Community support

Firestore

Free
  • SparkFree
    • 1GB storage
    • 50K reads/day
    • 20K writes/day
  • BlazeFree
    • Pay as you go
    • Unlimited operations
    • Multi-region

Which should you pick?

Choose Apache Pulsar if

  • You need separated storage.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want queuing and streaming.
Apache Pulsar review

Choose Firestore if

  • You need document model.
  • You want to start without paying.
  • You work on Web, Ios, Android, Flutter.
  • You also want real-time updates.
Firestore review

Questions people ask

Is Apache Pulsar or Firestore better?
Neither clearly leads. Apache Pulsar starts at Free and Firestore at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Apache Pulsar or Firestore?
Apache Pulsar starts at Free and Firestore at Free.
Does Apache Pulsar or Firestore run on more platforms?
Apache Pulsar runs on Linux, Docker, Kubernetes, Self-hosted. Firestore runs on Web, Ios, Android, Flutter.
Can I use Apache Pulsar for free?
Both have a free tier, so you can try either at no cost before committing.
What is Apache Pulsar best used for?
Apache Pulsar is most often used for platforms needing both work queues and replayable streams without running two systems, multi-tenant messaging where isolation between teams is a requirement, deployments where storage and traffic grow at genuinely different rates. Of those, platforms needing both work queues and replayable streams without running two systems and multi-tenant messaging where isolation between teams is a requirement are not what Firestore is typically brought in for.
What can Apache Pulsar do that Firestore cannot?
Apache Pulsar covers Separated storage, Queuing and streaming, Built-in multi-tenancy, Geo-replication. Firestore covers Document Model, Real-time Updates, Offline Support, ACID Transactions.

Answered from the vendors’ own pages

Apache Pulsar: Is Apache Pulsar free?

Yes, open source under the Apache Software Foundation.

Firestore: What are the free limits on Cloud Firestore?

The Spark Plan includes 1 GiB of stored data, 50,000 reads per day, 20,000 writes per day, and 20,000 deletes per day at no cost.

Source
Apache Pulsar: Pulsar or Kafka?

Pulsar separates storage from compute and covers queuing and streaming in one system. Kafka has a far larger ecosystem and hiring pool. Most teams should have a specific reason before choosing Pulsar.

Firestore: What happens when I exceed the Spark Plan free tier?

Exceeding the free tier requires upgrading to the Blaze Plan, which bills based on actual usage through Google Cloud pricing. Charges apply for reads, writes, deletes, and data storage.

Source
Apache Pulsar: Why does separated storage matter?

Brokers hold no data, so adding or replacing one requires no rebalancing, and storage can grow without adding serving capacity.

Firestore: Can I use Firestore without a credit card?

Yes, you can use the Spark Plan indefinitely without a credit card. To use the Blaze Plan (pay-as-you-go), a credit card is required.

Source
Firestore: Is there a trial period for Cloud Firestore?

No trial period is specified. The Spark Plan free tier serves as the trial, with no time limit.

Source
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