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Databases · head to head

Firestore vs Zilliz

Firestore logo

Firestore

Databases

Flexible, scalable NoSQL cloud database from Firebase

From
Free
Rated
-
Full reviewWebsite
Zilliz logo

Zilliz

Databases

Managed vector database and vector lakebase for AI applications

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Firestore the no-cost Spark plan caps Standard edition at 50,000 document reads, 20,000 writes and 20,000 deletes per day; Zilliz pricing structure not publicly disclosed, requires sales contact
  • They diverge on capability: Firestore covers Document Model, Zilliz covers Vector indexing.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Firestore and Zilliz actually diverge.

Attributes where Firestore and Zilliz differ
AttributeFirestoreZilliz
Pricing modelfreemiumcontact-sales
PlatformsWeb, Ios, Android, FlutterCloud, Self-hosted
Founded20112017

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 Firestore

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

Only in Zilliz

  • Vector indexing
  • Distributed architecture
  • SQL interface
  • Tensor support
  • Real-time search
  • Cloud-native
  • Open-source compatible

What people use each for

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

Firestore

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

Zilliz

  • Build retrieval-augmented generation (RAG) systemsnot Firestore
  • Implement semantic search over documentsnot Firestore
  • Create multimodal search with text and imagesnot Firestore
  • Power recommendation engines with vector similaritynot Firestore
  • Enable similarity search on user embeddingsnot Firestore

Where each one falls short

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

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

Zilliz

  • Pricing structure not publicly disclosed, requires sales contact
  • Operational complexity for self-hosted Milvus deployments
  • Learning curve for those unfamiliar with vector databases
  • Limited built-in analytics compared to some alternatives

Pricing, plan by plan

Firestore

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

Zilliz

Free

No published plan breakdown. See the Zilliz review.

Which should you pick?

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

Choose Zilliz if

  • You need vector indexing.
  • You want to start without paying.
  • You work on Cloud, Self-hosted.
  • You also want distributed architecture.
Zilliz review

Questions people ask

Is Firestore or Zilliz better?
Neither clearly leads. Firestore starts at Free and Zilliz at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Firestore or Zilliz?
Firestore starts at Free and Zilliz at Free.
Does Firestore or Zilliz run on more platforms?
Firestore runs on Web, Ios, Android, Flutter. Zilliz runs on Cloud, Self-hosted.
Can I use Firestore for free?
Both have a free tier, so you can try either at no cost before committing.
What is Firestore best used for?
Firestore is most often used for storing structured application data with realtime listeners, backing mobile and web apps with a serverless document database, building offline first apps that sync when connectivity returns. Of those, storing structured application data with realtime listeners and backing mobile and web apps with a serverless document database are not what Zilliz is typically brought in for.
What can Firestore do that Zilliz cannot?
Firestore covers Document Model, Real-time Updates, Offline Support, ACID Transactions. Zilliz covers Vector indexing, Distributed architecture, SQL interface, Tensor support.

Answered from the vendors’ own pages

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
Zilliz: What is the difference between Milvus and Zilliz Cloud?

Milvus is the open-source vector database that you can self-host. Zilliz Cloud is the fully managed service built on Milvus that removes operational overhead and handles scaling automatically.

Source
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
Zilliz: How many vectors can Zilliz handle?

Milvus and Zilliz Cloud can store and search billions of vectors through their distributed architecture that separates storage and compute layers.

Source
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
Zilliz: Is Milvus open-source?

Yes, Milvus is open-source under the Apache License 2.0 and is part of the LF AI & Data Foundation.

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
Zilliz: What pricing does Zilliz Cloud offer?

Zilliz Cloud pricing is not publicly listed and requires contacting their team to discuss your specific scale and use case requirements.

Source
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