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Databases · head to head

CosmosDB vs Xata

CosmosDB logo

CosmosDB

Databases

Globally distributed, multi-model database service from Azure

From
Free
Rated
-
Full reviewWebsite
Xata logo

Xata

Databases

Apache 2.0 platform for running many Postgres instances on Kubernetes, with copy-on-write branching and scale-to-zero.

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: CosmosDB autoscale provisioned throughput enforces a minimum of 1,000 RU/s, billed hourly whether or not the database is used; Xata self-hosting means operating Kubernetes and CloudNativePG, so the Apache 2.0 licence removes the vendor bill but replaces it with a platform team, and a database platform is not something a part-time operator maintains safely.
  • They diverge on capability: CosmosDB covers Global Distribution, Xata covers Copy-on-write branching.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which CosmosDB and Xata actually diverge.

Attributes where CosmosDB and Xata differ
AttributeCosmosDBXata
PlatformsWeb, AzureWeb
Founded1975Unknown

Identical on both: starting price (Free), pricing model (usage-based), 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 CosmosDB

  • Global Distribution
  • Multi-model APIs
  • Elastic Scaling
  • Five Consistency Levels
  • SLA-backed Latency
  • Automatic Indexing
  • Serverless
  • Azure Functions

Only in Xata

  • Copy-on-write branching
  • Scale-to-zero compute
  • Compute autoscaling and bin-packing
  • High availability with failover
  • Point-in-time recovery
  • Serverless driver
  • pgroll migrations
  • pgstream replication

What people use each for

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

CosmosDB

  • Running a globally distributed multi model database on Azurenot Xata
  • Serving low latency reads and writes from multiple Azure regionsnot Xata
  • Storing document, key value and graph data behind a managed servicenot Xata

Xata

  • Giving every pull request or coding agent its own branch of the production database, with real data volumes rather than a seeded fixturenot CosmosDB
  • Running managed-Postgres economics in your own cloud account where data residency or compliance rules out a third-party control planenot CosmosDB
  • Consolidating many small, mostly idle Postgres databases onto shared infrastructure where scale-to-zero and bin-packing recover the idle costnot CosmosDB
  • Testing a destructive migration against a copy of production without waiting for a full restore or paying for a duplicate of the storagenot CosmosDB

Where each one falls short

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

CosmosDB

  • Autoscale provisioned throughput enforces a minimum of 1,000 RU/s, billed hourly whether or not the database is used
  • Provisioned throughput is charged in every region the account is replicated to, so multi region accounts multiply the RU bill
  • Storage charges cover data, indexes and backups in each replicated region
  • Egress out of Azure and between regions is charged, though ingress is free
  • The free allowance is one account per Azure subscription, limited to 1,000 RU/s and 25 GB
  • RU/s rates vary by region and are only shown through the pricing calculator rather than a flat published rate

Xata

  • Self-hosting means operating Kubernetes and CloudNativePG, so the Apache 2.0 licence removes the vendor bill but replaces it with a platform team, and a database platform is not something a part-time operator maintains safely.
  • Copy-on-write branches are cheap to create but diverge as they are written to, so a long-lived branch carrying a heavy backfill quietly accumulates real storage and the cost arrives later than the decision that caused it.
  • Scale-to-zero means the first connection after an idle period pays a cold start, which is invisible in a busy production database and very visible in a demo, a staging environment or a cron job that runs once an hour.
  • The Xata sold before 2025 was a different product, a proprietary API and SDK layered over Postgres, so tutorials, blog posts and SDK examples from that era describe something that no longer exists and existing users had to migrate.
  • As a managed service it competes with RDS, Aurora and Cloud SQL, and it is a much smaller company, so procurement, certification coverage and the depth of the support bench behind a 3am corruption incident are all weaker than the incumbent even though the underlying Postgres is the same.

Pricing, plan by plan

CosmosDB

Free
  • Free TierFree
    • 1000 RU/s
    • 25GB storage
    • First 12 months
  • ServerlessFree
    • Pay per request
    • Auto-scaling
    • Event-driven workloads

Xata

Free
  • Free TrialFree
    • 14 days free
    • No credit card required
  • Usage-Based$1/per 1000 branches
    • 1,000 branches for $1
    • Scale-to-zero compute model
    • Branches hibernate when idle

Which should you pick?

Choose CosmosDB if

  • You need global distribution.
  • You want to start without paying.
  • You work on Web, Azure.
  • You also want multi-model apis.
CosmosDB review

Choose Xata if

  • You need copy-on-write branching.
  • You want to start without paying.
  • You also want scale-to-zero compute.
Xata review

Questions people ask

Is CosmosDB or Xata better?
Neither clearly leads. CosmosDB starts at Free and Xata at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, CosmosDB or Xata?
CosmosDB starts at Free and Xata at Free.
Does CosmosDB or Xata run on more platforms?
CosmosDB runs on Web, Azure. Xata runs on Web.
Can I use CosmosDB for free?
Both have a free tier, so you can try either at no cost before committing.
What is CosmosDB best used for?
CosmosDB is most often used for running a globally distributed multi model database on azure, serving low latency reads and writes from multiple azure regions, storing document, key value and graph data behind a managed service. Of those, running a globally distributed multi model database on azure and serving low latency reads and writes from multiple azure regions are not what Xata is typically brought in for.
What can CosmosDB do that Xata cannot?
CosmosDB covers Global Distribution, Multi-model APIs, Elastic Scaling, Five Consistency Levels. Xata covers Copy-on-write branching, Scale-to-zero compute, Compute autoscaling and bin-packing, High availability with failover.

Answered from the vendors’ own pages

CosmosDB: Is there a free tier for Azure Cosmos DB?

Yes, Cosmos DB offers a free tier with 1,000 RU/s of throughput and 25 GB of storage per month for the lifetime of the account, available to new accounts.

Source
Xata: Is it real Postgres or a compatible reimplementation?

Real Postgres. It runs upstream Postgres instances on Kubernetes via CloudNativePG, so extensions, the wire protocol and version upgrades behave as they do anywhere else.

CosmosDB: How is Cosmos DB priced after the free tier?

Cosmos DB uses three billing models: provisioned throughput billed per request unit per second, vCore pricing for certain APIs, or serverless consumption pricing where you pay only for requests processed. Reserved capacity offers 20% discount for one year or 30% for three years.

Source
Xata: Can I self-host the whole thing?

Yes. The platform is Apache 2.0 and designed for self-hosting a large number of Postgres instances on your own Kubernetes. Xata Cloud is the same platform run as a service.

CosmosDB: Can I change my pricing model after choosing one?

No. Once you select a compute pricing model and API, they cannot be changed. This choice is permanent for that database.

Source
Xata: Does branching copy my data?

No. Branches are copy-on-write at the storage layer, so creating one is near-instant regardless of database size and storage is only consumed as the branch diverges from its parent.

CosmosDB: Is there a trial period for Cosmos DB beyond the free tier?

Azure offers a 30-day free trial account for all Azure services. Additionally, Azure AI customers may be eligible for a 90-day free Cosmos DB subscription through the Azure AI Advantage program.

Source
Xata: Is this the same Xata I used a couple of years ago?

No. The earlier product was a proprietary database API with its own SDK and search layer. The current product is a Postgres platform, and material written for the old one does not apply.

Xata: What happens to a branch when the parent changes?

A branch is a point-in-time fork. Later changes on the parent are not propagated, so long-lived branches drift and need to be recreated rather than refreshed if you want current data.

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