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Databases · head to head

Firebase Realtime Database vs Redis

Firebase Realtime Database logo

Firebase Realtime Database

Databases

Store and sync data in real-time across all clients

From
Free
Rated
-
Full reviewWebsite
Redis logo

Redis

Technology

The real-time data platform

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Firebase Realtime Database the no-cost Spark plan caps storage at 1 GB, downloads at 10 GB per month and simultaneous connections at 100; Redis licensing changed from BSD to AGPL in 2025, impacting open-source usage
  • They diverge on capability: Firebase Realtime Database covers Real-time Sync, Redis covers In-memory data store.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Firebase Realtime Database and Redis actually diverge.

Attributes where Firebase Realtime Database and Redis differ
AttributeFirebase Realtime DatabaseRedis
Pricing modelfreemiumUnknown
PlatformsWeb, Ios, AndroidLinux, macOS, Windows
CategoryDatabasesTechnology
Founded20112009

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

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 Firebase Realtime Database

  • Real-time Sync
  • Offline Support
  • JSON Storage
  • Security Rules
  • Data Validation
  • Multi-platform SDKs
  • Scalable
  • Firebase Auth

Only in Redis

  • In-memory data store
  • Data structures
  • Pub/Sub messaging
  • Lua scripting
  • Transactions
  • Persistence options
  • Replication
  • Clustering

What people use each for

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

Firebase Realtime Database

  • Syncing JSON application state between clients in real timenot Redis
  • Backing mobile and web apps with offline capable data storagenot Redis
  • Prototyping realtime features such as presence and chatnot Redis

Redis

  • Cachingnot Firebase Realtime Database
  • Session managementnot Firebase Realtime Database
  • Real-time analyticsnot Firebase Realtime Database
  • Message queuingnot Firebase Realtime Database
  • Leaderboardsnot Firebase Realtime Database

Where each one falls short

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

Firebase Realtime Database

  • The no-cost Spark plan caps storage at 1 GB, downloads at 10 GB per month and simultaneous connections at 100
  • The Spark plan does not support multiple databases in a project
  • Even on the paid Blaze plan simultaneous connections are capped at 200,000 per database
  • Billing is by data transferred out at $1 per GB plus $5 per GB stored, so chatty clients cost more than the data volume suggests

Redis

  • Licensing changed from BSD to AGPL in 2025, impacting open-source usage
  • All data must fit in memory, limiting scalability to available RAM
  • No built-in support for multi-tenancy
  • Limited transaction support compared to traditional databases

Pricing, plan by plan

Firebase Realtime Database

Free
  • SparkFree
    • 1 GB data storage included
    • 10 GB per month data downloads included
    • No charges for usage within limits
  • Blaze$5/per_GB_per_month
    • Maintains Spark free allowances
    • Pay-as-you-go for usage exceeding limits
    • Billing applies to data stored and outbound network traffic

Redis

Free

No published plan breakdown. See the Redis review.

Which should you pick?

Choose Firebase Realtime Database if

  • You need real-time sync.
  • You want to start without paying.
  • You work on Web, Ios, Android.
  • You also want offline support.
Firebase Realtime Database review

Choose Redis if

  • You need in-memory data store.
  • You want to start without paying.
  • You work on Linux, macOS, Windows.
  • You also want data structures.
Redis review

Questions people ask

Is Firebase Realtime Database or Redis better?
Neither clearly leads. Firebase Realtime Database starts at Free and Redis at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Firebase Realtime Database or Redis?
Firebase Realtime Database starts at Free and Redis at Free.
Does Firebase Realtime Database or Redis run on more platforms?
Firebase Realtime Database runs on Web, Ios, Android. Redis runs on Linux, macOS, Windows.
Can I use Firebase Realtime Database for free?
Both have a free tier, so you can try either at no cost before committing.
What is Firebase Realtime Database best used for?
Firebase Realtime Database is most often used for syncing json application state between clients in real time, backing mobile and web apps with offline capable data storage, prototyping realtime features such as presence and chat. Of those, syncing json application state between clients in real time and backing mobile and web apps with offline capable data storage are not what Redis is typically brought in for.
What can Firebase Realtime Database do that Redis cannot?
Firebase Realtime Database covers Real-time Sync, Offline Support, JSON Storage, Security Rules. Redis covers In-memory data store, Data structures, Pub/Sub messaging, Lua scripting.

Answered from the vendors’ own pages

Firebase Realtime Database: How much does Firebase Realtime Database cost?

Firebase Realtime Database offers a free Spark plan (1 GB storage, 10 GB/month downloads) and a pay-as-you-go Blaze plan. On Blaze, storage costs $5 per GB per month, evaluated daily, with no monthly minimum charges.

Source
Redis: Is Redis open source?

Redis was open source under the BSD license since its inception in 2009 and has remained open source. However, in 2024-2025, Redis Labs changed licensing to source-available and AGPL, prompting the creation of Valkey, a BSD-licensed open-source fork.

Source
Firebase Realtime Database: What is included in Firebase Realtime Database free tier?

The Spark plan includes 1 GB of data storage and 10 GB per month of data downloads at no cost. Usage within these limits incurs no charges, making it suitable for small projects and testing.

Source
Redis: What is Redis used for?

Redis is an in-memory data structure store used primarily as a cache, database, and message broker. It provides high-speed data access for real-time applications, sessions, leaderboards, real-time analytics, and other use cases requiring fast data retrieval.

Source
Firebase Realtime Database: Does Firebase Realtime Database charge for denied or rejected operations?

Yes. Firebase charges for all traffic to and from the database on the Blaze plan, including operations denied by security rules, outbound network traffic at the session layer, and connection and encryption overhead from all operations.

Source
Firebase Realtime Database: Can I set a spending limit on Firebase Realtime Database?

Firebase offers budget alerts but does not cap spending automatically. Users must monitor their usage dashboard in the Firebase console to track connections, storage, downloads, and load metrics; a calculator is available for cost estimation.

Source
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