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Databases · head to head

Apache Solr vs Firestore

Apache Solr logo

Apache Solr

Databases

Enterprise search platform built on Apache Lucene

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 Solr xML-heavy configuration and a developer experience that feels dated beside newer engines; 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 Solr covers Lucene-based indexing, Firestore covers Document Model.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

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

Attributes where Apache Solr and Firestore differ
AttributeApache SolrFirestore
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 Solr

  • Lucene-based indexing
  • Faceted search
  • SolrCloud
  • Schema control

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 Solr

  • Library, archive and catalogue search where faceting is centralnot Firestore
  • Long-lived enterprise deployments valuing stability over noveltynot Firestore
  • Search requiring precise, explicitly configured relevance tuningnot Firestore

Firestore

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

Where each one falls short

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

Apache Solr

  • XML-heavy configuration and a developer experience that feels dated beside newer engines
  • SolrCloud depends on ZooKeeper, adding a component Elasticsearch removed years ago
  • Smaller mindshare now, so newer tutorials, hiring and integrations favour Elasticsearch
  • Considerably heavier than a purpose-built application search engine

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 Solr

Free
  • Apache SolrFree
    • 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 Solr if

  • You need lucene-based indexing.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want faceted search.
Apache Solr 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 Solr or Firestore better?
Neither clearly leads. Apache Solr 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 Solr or Firestore?
Apache Solr starts at Free and Firestore at Free.
Does Apache Solr or Firestore run on more platforms?
Apache Solr runs on Linux, Docker, Kubernetes, Self-hosted. Firestore runs on Web, Ios, Android, Flutter.
Can I use Apache Solr for free?
Both have a free tier, so you can try either at no cost before committing.
What is Apache Solr best used for?
Apache Solr is most often used for library, archive and catalogue search where faceting is central, long-lived enterprise deployments valuing stability over novelty, search requiring precise, explicitly configured relevance tuning. Of those, library, archive and catalogue search where faceting is central and long-lived enterprise deployments valuing stability over novelty are not what Firestore is typically brought in for.
What can Apache Solr do that Firestore cannot?
Apache Solr covers Lucene-based indexing, Faceted search, SolrCloud, Schema control. Firestore covers Document Model, Real-time Updates, Offline Support, ACID Transactions.

Answered from the vendors’ own pages

Apache Solr: Is Apache Solr 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 Solr: Solr or Elasticsearch?

Both are built on Lucene. Elasticsearch has the larger ecosystem and a friendlier API; Solr is very mature and strong on faceted search, and remains common in library and catalogue systems.

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 Solr: Is Solr still maintained?

Yes, actively, as a top-level Apache project.

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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