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Firebase Realtime Database vs Memcached

Firebase Realtime Database logo

Firebase Realtime Database

Databases

Store and sync data in real-time across all clients

From
Free
Rated
-
Full reviewWebsite
M

Memcached

Databases

Distributed memory object caching system

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; Memcached no persistence at all: restart a node and its cache is gone, which every design must assume
  • They diverge on capability: Firebase Realtime Database covers Real-time Sync, Memcached covers In-memory key-value cache.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

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

Attributes where Firebase Realtime Database and Memcached differ
AttributeFirebase Realtime DatabaseMemcached
Pricing modelfreemiumOpen source, no licence fee; managed cloud billed separately
PlatformsWeb, Ios, AndroidLinux, macOS, Windows, Docker, Self-hosted
Founded2011Unknown

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 Firebase Realtime Database

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

Only in Memcached

  • In-memory key-value cache
  • Multithreaded
  • Client-side sharding
  • Predictable memory use

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 Memcached
  • Backing mobile and web apps with offline capable data storagenot Memcached
  • Prototyping realtime features such as presence and chatnot Memcached

Memcached

  • Caching expensive database query results to cut loadnot Firebase Realtime Database
  • Session storage where losing sessions on restart is acceptablenot Firebase Realtime Database
  • Fronting an API whose responses are costly and change slowlynot 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

Memcached

  • No persistence at all: restart a node and its cache is gone, which every design must assume
  • No replication or failover, so losing a node loses that share of the cache
  • Only simple key-value, with none of the lists, sorted sets or streams Redis offers
  • Values are capped at 1MB by default, which surprises teams caching large documents

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

Memcached

Free
  • MemcachedFree
    • Full functionality
    • Self-hosted
    • No usage limits

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 Memcached if

  • You need in-memory key-value cache.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker, Self-hosted.
  • You also want multithreaded.
Memcached review

Questions people ask

Is Firebase Realtime Database or Memcached better?
Neither clearly leads. Firebase Realtime Database starts at Free and Memcached at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Firebase Realtime Database or Memcached?
Firebase Realtime Database starts at Free and Memcached at Free.
Does Firebase Realtime Database or Memcached run on more platforms?
Firebase Realtime Database runs on Web, Ios, Android. Memcached runs on Linux, macOS, Windows, Docker, Self-hosted.
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 Memcached is typically brought in for.
What can Firebase Realtime Database do that Memcached cannot?
Firebase Realtime Database covers Real-time Sync, Offline Support, JSON Storage, Security Rules. Memcached covers In-memory key-value cache, Multithreaded, Client-side sharding, Predictable memory use.

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
Memcached: Is Memcached free?

Yes, open source with no licence fee.

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
Memcached: Memcached or Redis?

Memcached is a pure cache: simpler, multithreaded and very predictable. Redis adds persistence, replication and rich data structures, which is why it is the default choice unless you specifically want a cache and nothing more.

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
Memcached: Does Memcached persist data?

No. Everything is in memory and lost on restart, by design.

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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