Software · head to head
Convex vs Cassandra
Convex
Software
The reactive backend platform that keeps up with you and your agents
- From
- On request
- Rated
- -
Cassandra
Software
Manage massive amounts of data with linear scalability
- From
- Free
- Rated
- -
The short version
- Only Cassandra has a free tier, so it costs nothing to try first.
- Each has a real cost: Convex the Free and Starter tier includes only 1 million function calls and 0.5 GB of database storage per month before per-unit overage charges of $2.20 per million calls apply, as of August 2026.; Cassandra no support for joins across tables
Where they differ
Only the attributes on which Convex and Cassandra actually diverge.
Identical on both: user rating (Not yet rated), category (Unknown).
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 Convex
Nothing recorded that Cassandra does not also cover.
Only in Cassandra
- Linear Scalability
- Fault Tolerance
- Multi-datacenter Replication
- Tunable Consistency
- CQL Query Language
- Distributed Architecture
- No Single Point of Failure
- DataStax
What people use each for
The jobs each tool is most often brought in to do.
Convex
No use cases recorded yet. See the Convex review.
Cassandra
- Real-time applicationsnot Convex
- Content managementnot Convex
- User profilesnot Convex
- Mobile backendsnot Convex
- Cachingnot Convex
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Convex
- The Free and Starter tier includes only 1 million function calls and 0.5 GB of database storage per month before per-unit overage charges of $2.20 per million calls apply, as of August 2026.
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
Pricing, plan by plan
Convex
On requestNo published plan breakdown. See the Convex review.
Cassandra
FreeNo published plan breakdown. See the Cassandra review.
Which should you pick?
Choose Convex if
Nothing in the data separates Convex from Cassandra on the points above - pick on price and on how each one feels to use.
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.
Questions people ask
- Is Convex or Cassandra better?
- Neither clearly leads. Convex starts at On request and Cassandra at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Convex or Cassandra?
- Cassandra has a free tier; the other does not. Paid plans start at On request for Convex and Free for Cassandra.
- Does Convex or Cassandra run on more platforms?
- Convex runs on Web. Cassandra runs on Linux, macOS, Windows, Docker, Kubernetes.
- Can I use Cassandra for free?
- Yes. Cassandra has a free tier, so you can try it without paying. Convex starts at On request.
- What can Convex do that Cassandra cannot?
- Cassandra covers Linear Scalability, Fault Tolerance, Multi-datacenter Replication, Tunable Consistency.
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.
SourceCassandra: 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.
SourceCassandra: 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.
SourceCassandra: 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.
SourceCassandra: 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