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Databases · head to head

Convex vs MotherDuck

Convex logo

Convex

Databases

Reactive backend combining a document database, TypeScript server functions and live queries, source-available under the Functional Source Licence.

From
Free
Rated
-
Full reviewWebsite
MotherDuck logo

MotherDuck

Databases

Serverless analytics data warehouse built on DuckDB

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Convex the Functional Source Licence is not an OSI open source licence: competing use is prohibited until each release reaches its second anniversary and converts to Apache 2.0, so you may self-host but you may not build a service on it.; MotherDuck the free Lite plan caps compute at 10 hours per month, which limits it to light or hobbyist workloads.
  • They diverge on capability: Convex covers Reactive queries, MotherDuck covers Serverless DuckDB instances.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Convex and MotherDuck actually diverge.

Attributes where Convex and MotherDuck differ
AttributeConvexMotherDuck
Pricing modelsubscriptionusage-based
PlatformsWebweb, api
FoundedUnknown2022

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 Convex

  • Reactive queries
  • TypeScript server functions
  • ACID transactions
  • Document database
  • Scheduling and workflows
  • File storage
  • Text and vector search
  • End-to-end types

Only in MotherDuck

  • Serverless DuckDB instances
  • Cloud storage querying
  • MCP server
  • Dives
  • Flights
  • Read-scaling replicas

What people use each for

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

Convex

  • Collaborative applications where several users see the same data and every client must reflect a change immediatelynot MotherDuck
  • Agent backends that need durable state, scheduled work and transactional writes without assembling a queue, a database and a cachenot MotherDuck
  • Small product teams who need a complete backend, including auth integration, file storage and subscriptions, without hiring infrastructure engineersnot MotherDuck
  • Prototypes that must become production without a rewrite of the data layer, where end-to-end TypeScript types remove a class of integration bugsnot MotherDuck

MotherDuck

  • Ad-hoc analytics on gigabyte-to-terabyte datasetsnot Convex
  • Querying data lake files in S3/GCS/Azure without ingestionnot Convex
  • AI agent data analysis via MCPnot Convex
  • Scheduled data pipeline transformationsnot Convex

Where each one falls short

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

Convex

  • The Functional Source Licence is not an OSI open source licence: competing use is prohibited until each release reaches its second anniversary and converts to Apache 2.0, so you may self-host but you may not build a service on it.
  • Transactions are bounded at one second of user code, 16 MiB read and written, 32,000 documents scanned and 16,000 written, so every backfill, migration or bulk import has to be chunked into scheduled batches rather than written as a single operation.
  • There is no SQL and no query planner; you declare up to 32 indexes per table and traverse them, and joins are loops in TypeScript, so an unanticipated access pattern requires a schema and index change rather than a new query.
  • It is not an analytical database, so reporting means streaming data out to a warehouse and BI tools cannot be pointed at Convex directly, which adds a pipeline the architecture diagram did not originally include.
  • The application is written against Convex's function and client APIs rather than a standard protocol, so leaving means rewriting the data access layer and replacing the reactivity model, not repointing a connection string.

MotherDuck

  • The free Lite plan caps compute at 10 hours per month, which limits it to light or hobbyist workloads.
  • Business plan usage charges on top of the $250/month base can make costs less predictable than flat-rate competitors.
  • There are no academic or non-profit discounts, unlike some competing data platforms.
  • Annual billing requires going through a sales conversation rather than a self-serve toggle.

Pricing, plan by plan

Convex

Free
  • Free & StarterFree
    • Supports 1-6 developers
    • Reactive database
    • File storage
  • Professional$25/month per developer
    • Supports up to 20 developers
    • All Starter features
    • Log streaming
  • Business & Enterprise$2500/month minimum
    • Supports 50+ developers
    • SAML/SSO
    • Service SLAs

MotherDuck

Free
  • LiteFree
    • Up to 3 internal active users
    • 2 service accounts
    • 10GB free storage
  • Business$250/month
    • Up to 10 internal active users
    • Unlimited service accounts
    • 5 instance types with read-scaling replicas
  • Enterprise$undefined/month
    • Unlimited internal users and service accounts
    • Fixed-cost capacity pricing
    • AWS PrivateLink, IP allowlisting

Which should you pick?

Choose Convex if

  • You need reactive queries.
  • You want to start without paying.
  • You also want typescript server functions.
Convex review

Choose MotherDuck if

  • You need serverless duckdb instances.
  • You want to start without paying.
  • You work on web, api.
  • You also want cloud storage querying.
MotherDuck review

Questions people ask

Is Convex or MotherDuck better?
Neither clearly leads. Convex starts at Free and MotherDuck at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Convex or MotherDuck?
Convex starts at Free and MotherDuck at Free.
Does Convex or MotherDuck run on more platforms?
Convex runs on Web. MotherDuck runs on web, api.
Can I use Convex for free?
Both have a free tier, so you can try either at no cost before committing.
What is Convex best used for?
Convex is most often used for collaborative applications where several users see the same data and every client must reflect a change immediately, agent backends that need durable state, scheduled work and transactional writes without assembling a queue, a database and a cache, small product teams who need a complete backend, including auth integration, file storage and subscriptions, without hiring infrastructure engineers, prototypes that must become production without a rewrite of the data layer, where end-to-end typescript types remove a class of integration bugs. Of those, collaborative applications where several users see the same data and every client must reflect a change immediately and agent backends that need durable state, scheduled work and transactional writes without assembling a queue, a database and a cache are not what MotherDuck is typically brought in for.
What can Convex do that MotherDuck cannot?
Convex covers Reactive queries, TypeScript server functions, ACID transactions, Document database. MotherDuck covers Serverless DuckDB instances, Cloud storage querying, MCP server, Dives.

Answered from the vendors’ own pages

Convex: Is Convex open source?

It is source-available under FSL-1.1-Apache-2.0. You may read, modify and self-host it, but competing use is prohibited until each release converts to Apache 2.0 on its second anniversary.

MotherDuck: What does MotherDuck cost?

The Lite plan is free (up to 3 users, 10GB storage, 10 hours of Pulse compute/month). Business is $250/organization/month plus usage, with Enterprise available at custom fixed-cost pricing.

Source
Convex: Can I self-host it?

Yes. The backend, dashboard and CLI can run on your own infrastructure, with most of the features of the cloud product. Self-hosted instances include a telemetry beacon that can be disabled.

MotherDuck: Is there a free plan and what are its limits?

Yes, the Lite plan is free for up to 3 internal active users and 2 service accounts, with 10GB of storage and 10 hours of Pulse compute per month.

Source
Convex: Does it support SQL?

No. Data is accessed through a TypeScript query builder over declared indexes. Relationships are traversed in code, which is explicit and type-safe but means no ad hoc querying.

MotherDuck: How is usage metered?

Compute instances (Pulse, Standard, Jumbo, Mega, Giga) are billed per second at hourly rates from $0.60 to $24.00/hour, storage is $0.04/GB-month, and AI Functions cost $1.00 per AI Unit.

Source
Convex: What happens if a mutation exceeds the limits?

It fails rather than running longer, so bulk work must be split into batches and scheduled. The limits are per transaction: one second of user code, 16 MiB read and written, 32,000 documents scanned and 16,000 written.

Convex: How does reactivity actually work?

Queries are deterministic functions and Convex records the data each one read. When a mutation changes that data, affected queries are re-run and subscribed clients receive the new result, so cache invalidation is handled by the platform.

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