Softwr

Machine Learning · head to head

Milvus vs MotherDuck

Milvus logo

Milvus

Machine Learning

Open-source vector database for scalable similarity search

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: Milvus vector dimensions are capped at 32,768; MotherDuck the free Lite plan caps compute at 10 hours per month, which limits it to light or hobbyist workloads.
  • They diverge on capability: Milvus covers Billion-scale vectors, MotherDuck covers Serverless DuckDB instances.

Where they differ

Only the attributes on which Milvus and MotherDuck actually diverge.

Attributes where Milvus and MotherDuck differ
AttributeMilvusMotherDuck
Pricing modelfreemiumusage-based
PlatformsLinux, Mac, Windows, Webweb, api
CategoryMachine LearningDatabases
Founded20172022

Identical on both: starting price (Free), 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 Milvus

  • Billion-scale vectors
  • Multiple index types
  • GPU acceleration
  • Hybrid search
  • Data partitioning
  • PyTorch
  • TensorFlow
  • Hugging Face

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.

Milvus

  • Self hosting a vector database for semantic searchnot MotherDuck
  • Storing and querying embeddings for retrieval augmented generationnot MotherDuck
  • Similarity search over images, audio or text at scalenot MotherDuck

MotherDuck

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

Where each one falls short

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

Milvus

  • Vector dimensions are capped at 32,768
  • A collection is limited to 64 fields, 1,024 partitions and 16 shards
  • Only 1 index is allowed per field
  • Search returns at most 16,384 vectors as top-k, and nq is capped at 16,384
  • Input and output per RPC is capped at 64 MB for insert, search and query
  • VARCHAR values are limited to 65,535 characters
  • Data loaded into query nodes cannot exceed 90% of available memory
  • An instance supports at most 65,536 collections

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

Milvus

Free
  • Open SourceFree
    • Full features
    • Self-hosted
    • Community support
  • Zilliz CloudFree
    • Managed service
    • Free tier available

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 Milvus if

  • You need billion-scale vectors.
  • You want to start without paying.
  • You work on Linux, Mac, Windows, Web.
  • You also want multiple index types.
Milvus 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 Milvus or MotherDuck better?
Neither clearly leads. Milvus 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, Milvus or MotherDuck?
Milvus starts at Free and MotherDuck at Free.
Does Milvus or MotherDuck run on more platforms?
Milvus runs on Linux, Mac, Windows, Web. MotherDuck runs on web, api.
Can I use Milvus for free?
Both have a free tier, so you can try either at no cost before committing.
What is Milvus best used for?
Milvus is most often used for self hosting a vector database for semantic search, storing and querying embeddings for retrieval augmented generation, similarity search over images, audio or text at scale. Of those, self hosting a vector database for semantic search and storing and querying embeddings for retrieval augmented generation are not what MotherDuck is typically brought in for.
What can Milvus do that MotherDuck cannot?
Milvus covers Billion-scale vectors, Multiple index types, GPU acceleration, Hybrid search. MotherDuck covers Serverless DuckDB instances, Cloud storage querying, MCP server, Dives.

Answered from the vendors’ own pages

Milvus: How much does Milvus cost?

Milvus is open-source and free to use and modify. The self-hosted version has no licensing cost. Zilliz Cloud (the managed SaaS version) does not publish pricing on the website.

Source
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
Milvus: Is there a free or open-source version of Milvus?

Yes, Milvus is fully open-source and available for free. Milvus Lite is a lightweight option for learning and prototyping that can be installed via pip.

Source
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
Milvus: Does Milvus offer a managed cloud service?

Yes, Zilliz Cloud is a fully managed Milvus cloud offering with serverless and dedicated cluster options. Pricing must be requested from the company as it is not listed on the public website.

Source
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
Share

Related pages

More on Milvus

More on MotherDuck

Keep looking

Other head to heads