Choose a database: Cloud Firestore or Realtime Database

Firebase offers two cloud-based, client-accessible database solutions that support realtime data syncing:

  • Cloud Firestore is Firebase's newest database for mobile app development. It builds on the successes of the Realtime Database with a new, more intuitive data model. Cloud Firestore also features richer, faster queries and scales further than the Realtime Database.

  • Realtime Database is Firebase's original database. It's an efficient, low-latency solution for mobile apps that require synced states across clients in realtime.

Which database is right for your project?

We recommend Cloud Firestore for most developers starting a new project. Cloud Firestore offers additional functionality, performance, and scalability on an infrastructure designed to support more powerful features in future releases. Expect to see new query types, more robust security rules, and improvements to performance among the advanced features planned for Cloud Firestore.

As you're choosing between database solutions, consider the following differences between Cloud Firestore and the Realtime Database.

Data model

Both Realtime Database and Cloud Firestore are NoSQL Databases.

Realtime Database Cloud Firestore
Stores data as one large JSON tree.
  • Simple data is very easy to store.
  • Complex, hierarchical data is harder to organize at scale.

Learn more about the Realtime Database data model.

 Stores data as collections of documents.
  • Simple data is easy to store in documents, which are very similar to JSON.
  • Complex, hierarchical data is easier to organize at scale, using subcollections within documents.
  • Requires less denormalization and data flattening.

Learn more about the Cloud Firestore data model.

Realtime and offline support

Both have mobile-first, realtime SDKs and both support local data storage for offline-ready apps.

Realtime Database Cloud Firestore
Offline support for iOS and Android clients. Offline support for iOS, Android, and web clients.

Presence

It can be useful to know when a client is online or offline. Firebase Realtime Database can record client connection status and provide updates every time the client's connection state changes.

Realtime Database Cloud Firestore
Presence supported. Not supported natively. You can leverage Realtime Database's support for presence by syncing Cloud Firestore and Realtime Database using Cloud Functions. See Build presence in Cloud Firestore.

Querying

Retrieve, sort, and filter data from either database through queries.

Realtime Database Cloud Firestore
Deep queries with limited sorting and filtering functionality.
  • Queries can sort or filter on a property, but not both.
  • Queries are deep by default: they always return the entire subtree.
  • Queries can access data at any granularity, down to individual leaf-node values in the JSON tree.
  • Queries do not require an index; however the performance of certain queries degrades as your data set grows.
 Indexed queries with compound sorting and filtering.
  • You can chain filters and combine filtering and sorting on a property in a single query.
  • Queries are shallow: they only return documents in a particular collection or collection group and do not return subcollection data.
  • Queries must always return whole documents.
  • Queries are indexed by default: Query performance is proportional to the size of your result set, not your data set.

Writes and transactions

Realtime Database Cloud Firestore
Basic write and transaction operations. Advanced write and transaction operations.
  • Write data operations through set and update operations as well as advanced transformations such as array and numeric operators.
  • Transactions can atomically read and write data from any part of the database.

Reliability and performance

Realtime Database Cloud Firestore
Realtime Database is a single-region solution.
  • Databases are limited to zonal availability in a single region.
  • Extremely low latency, ideal option for frequent state-syncing.
Read more about Realtime Database performance and reliability characteristics in the Service Level Agreement. 		Cloud Firestore is a multi-region solution that scales automatically.
  • Houses your data across multiple data centers in distinct regions, ensuring global scalability and strong reliability.
  • Available in regional or multi-regional configurations around the world.
Read more about Cloud Firestore performance and reliability characteristics in the Service Level Agreement.

Scalability

Realtime Database Cloud Firestore
Scaling requires sharding.
  • Scale to around 200,000 concurrent connections and 1,000 writes/second in a single database. Scaling beyond that requires sharding your data across multiple databases.
  • No local limits on write rates to individual pieces of data.
 Scaling is automatic.
  • Scales completely automatically. Currently, scaling limits are around 1 million concurrent connections and 10,000 writes/second. We plan to increase these limits in the future.
  • Has limits on write rates to individual documents or indexes.

Security

Realtime Database Cloud Firestore
Cascading rules language that separates authorization and validation. Non-cascading rules that combine authorization and validation.
  • Reads and writes from mobile SDKs secured by Cloud Firestore Security Rules.
  • Reads and writes from server SDKs secured by Identity and Access Management (IAM).
  • Rules don't cascade unless you use a wildcard.
  • Rules can constrain queries: If a query's results might contain data the user doesn't have access to, the entire query fails.

Pricing

Both solutions are available on the Spark, Flame, and Blaze pricing plans.

Realtime Database Cloud Firestore
Charges only for bandwidth and storage, but at a higher rate.

Read more about Realtime Database pricing plans.

 Charges primarily on operations performed in your database (read, write, delete) and, at a lower rate, bandwidth and storage.

Read more about Cloud Firestore pricing plans.

Using Cloud Firestore and Realtime Database

You can use both databases within the same Firebase app or project. Both NoSQL databases can store the same types of data and the client libraries work in a similar manner. Keep in mind the differences outlined above if you decide to use both databases in your app.

Learn more about the features available in both Realtime Database and Cloud Firestore.

Ready to choose a database?

Hopefully this comparison has helped you settle on a Firebase database solution. Now you can learn how to add a database to your Firebase projects.