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Databases · head to head

Cassandra vs Redis

Cassandra logo

Cassandra

Databases

Manage massive amounts of data with linear scalability

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: Cassandra no support for joins across tables; Redis licensing changed from BSD to AGPL in 2025, impacting open-source usage
  • They diverge on capability: Cassandra covers Linear Scalability, 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 Cassandra and Redis actually diverge.

Attributes where Cassandra and Redis differ
AttributeCassandraRedis
PlatformsLinux, macOS, Windows, Docker, KubernetesLinux, macOS, Windows
CategoryDatabasesTechnology
Founded20082009

Identical on both: starting price (Free), pricing model (Unknown), 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 Cassandra

  • Linear Scalability
  • Fault Tolerance
  • Multi-datacenter Replication
  • Tunable Consistency
  • CQL Query Language
  • Distributed Architecture
  • No Single Point of Failure
  • DataStax

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.

Cassandra

  • Real-time applicationsnot Redis
  • Content managementnot Redis
  • User profilesnot Redis
  • Mobile backendsnot Redis
  • Caching

Redis

  • Caching
  • Session managementnot Cassandra
  • Real-time analyticsnot Cassandra
  • Message queuingnot Cassandra
  • Leaderboardsnot Cassandra

Both are used for caching, on those jobs the choice comes down to price and fit rather than capability.

Where each one falls short

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

Cassandra

  • No support for joins across tables
  • No ACID transactions across multiple rows
  • Data model must be designed around query patterns upfront, making schema evolution difficult
  • Partition key misconfigurations can cause uneven data distribution and hotspots that degrade performance

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

Cassandra

Free

No published plan breakdown. See the Cassandra review.

Redis

Free

No published plan breakdown. See the Redis review.

Which should you pick?

Choose Cassandra if

  • You need linear scalability.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker, Kubernetes.
  • You also want fault tolerance.
Cassandra 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 Cassandra or Redis better?
Neither clearly leads. Cassandra 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, Cassandra or Redis?
Cassandra starts at Free and Redis at Free.
Does Cassandra or Redis run on more platforms?
Cassandra runs on Linux, macOS, Windows, Docker, Kubernetes. Redis runs on Linux, macOS, Windows.
Can I use Cassandra for free?
Both have a free tier, so you can try either at no cost before committing.
What is Cassandra best used for?
Cassandra is most often used for real-time applications, content management, user profiles, mobile backends. Of those, real-time applications and content management are not what Redis is typically brought in for.
What can Cassandra do that Redis cannot?
Cassandra covers Linear Scalability, Fault Tolerance, Multi-datacenter Replication, Tunable Consistency. Redis covers In-memory data store, Data structures, Pub/Sub messaging, Lua scripting.

Answered from the vendors’ own pages

Cassandra: Does Cassandra support joins between tables?

No. Cassandra does not support joins or foreign keys. The data model requires denormalization, meaning data must be duplicated across tables to support different query patterns.

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
Cassandra: Does Cassandra offer ACID transactions?

No. Cassandra provides only row-level atomicity and isolation, not full ACID transactions across multiple rows or tables. It uses lightweight transactions via Paxos for per-row compare-and-set operations.

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
Cassandra: What programming languages can connect to Cassandra?

Cassandra supports official drivers for multiple languages including Python, Java, Node.js, and Go, allowing applications to communicate via the native Cassandra protocol.

Source
Cassandra: Can I deploy Cassandra in the cloud?

Yes. Cassandra can run on any cloud platform (AWS, Google Cloud, Azure) via Docker, virtual machines, or managed services like DataStax Astra DB, which provides a fully managed DBaaS option.

Source
Cassandra: Does Cassandra have a free option?

The open source Apache Cassandra is free. DataStax also offers Astra DB with a free tier providing up to 25GB storage and 25 million read/write operations per month.

Source
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