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Databases · head to head

Apache Solr vs CosmosDB

Apache Solr logo

Apache Solr

Databases

Enterprise search platform built on Apache Lucene

From
Free
Rated
-
Full reviewWebsite
CosmosDB logo

CosmosDB

Databases

Globally distributed, multi-model database service from Azure

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; CosmosDB autoscale provisioned throughput enforces a minimum of 1,000 RU/s, billed hourly whether or not the database is used
  • They diverge on capability: Apache Solr covers Lucene-based indexing, CosmosDB covers Global Distribution.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

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

Attributes where Apache Solr and CosmosDB differ
AttributeApache SolrCosmosDB
Pricing modelOpen source, no licence feeusage-based
PlatformsLinux, Docker, Kubernetes, Self-hostedWeb, Azure
FoundedUnknown1975

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 CosmosDB

  • Global Distribution
  • Multi-model APIs
  • Elastic Scaling
  • Five Consistency Levels
  • SLA-backed Latency
  • Automatic Indexing
  • Serverless
  • Azure Functions

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 CosmosDB
  • Long-lived enterprise deployments valuing stability over noveltynot CosmosDB
  • Search requiring precise, explicitly configured relevance tuningnot CosmosDB

CosmosDB

  • Running a globally distributed multi model database on Azurenot Apache Solr
  • Serving low latency reads and writes from multiple Azure regionsnot Apache Solr
  • Storing document, key value and graph data behind a managed servicenot 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

CosmosDB

  • Autoscale provisioned throughput enforces a minimum of 1,000 RU/s, billed hourly whether or not the database is used
  • Provisioned throughput is charged in every region the account is replicated to, so multi region accounts multiply the RU bill
  • Storage charges cover data, indexes and backups in each replicated region
  • Egress out of Azure and between regions is charged, though ingress is free
  • The free allowance is one account per Azure subscription, limited to 1,000 RU/s and 25 GB
  • RU/s rates vary by region and are only shown through the pricing calculator rather than a flat published rate

Pricing, plan by plan

Apache Solr

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

CosmosDB

Free
  • Free TierFree
    • 1000 RU/s
    • 25GB storage
    • First 12 months
  • ServerlessFree
    • Pay per request
    • Auto-scaling
    • Event-driven workloads

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 CosmosDB if

  • You need global distribution.
  • You want to start without paying.
  • You work on Web, Azure.
  • You also want multi-model apis.
CosmosDB review

Questions people ask

Is Apache Solr or CosmosDB better?
Neither clearly leads. Apache Solr starts at Free and CosmosDB at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Apache Solr or CosmosDB?
Apache Solr starts at Free and CosmosDB at Free.
Does Apache Solr or CosmosDB run on more platforms?
Apache Solr runs on Linux, Docker, Kubernetes, Self-hosted. CosmosDB runs on Web, Azure.
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 CosmosDB is typically brought in for.
What can Apache Solr do that CosmosDB cannot?
Apache Solr covers Lucene-based indexing, Faceted search, SolrCloud, Schema control. CosmosDB covers Global Distribution, Multi-model APIs, Elastic Scaling, Five Consistency Levels.

Answered from the vendors’ own pages

Apache Solr: Is Apache Solr free?

Yes, open source under the Apache Software Foundation.

CosmosDB: Is there a free tier for Azure Cosmos DB?

Yes, Cosmos DB offers a free tier with 1,000 RU/s of throughput and 25 GB of storage per month for the lifetime of the account, available to new accounts.

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.

CosmosDB: How is Cosmos DB priced after the free tier?

Cosmos DB uses three billing models: provisioned throughput billed per request unit per second, vCore pricing for certain APIs, or serverless consumption pricing where you pay only for requests processed. Reserved capacity offers 20% discount for one year or 30% for three years.

Source
Apache Solr: Is Solr still maintained?

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

CosmosDB: Can I change my pricing model after choosing one?

No. Once you select a compute pricing model and API, they cannot be changed. This choice is permanent for that database.

Source
CosmosDB: Is there a trial period for Cosmos DB beyond the free tier?

Azure offers a 30-day free trial account for all Azure services. Additionally, Azure AI customers may be eligible for a 90-day free Cosmos DB subscription through the Azure AI Advantage program.

Source
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