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Machine Learning · head to head

Milvus vs Unleash

Milvus logo

Milvus

Machine Learning

Open-source vector database for scalable similarity search

From
Free
Rated
-
Full reviewWebsite
Unleash logo

Unleash

Software Development

Open-source feature flag and experimentation service

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Milvus vector dimensions are capped at 32,768; Unleash the Pay-As-You-Go plan is priced per seat, which can get costly for larger teams.
  • They diverge on capability: Milvus covers Billion-scale vectors, Unleash covers Feature flags.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Milvus and Unleash actually diverge.

Attributes where Milvus and Unleash differ
AttributeMilvusUnleash
PlatformsLinux, Mac, Windows, Webweb, api, linux
CategoryMachine LearningSoftware Development
Founded2017Unknown

Identical on both: starting price (Free), pricing model (freemium), 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 Unleash

  • Feature flags
  • A/B/n testing
  • Custom targeting
  • SDKs
  • SSO
  • Audit logs

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 Unleash
  • Storing and querying embeddings for retrieval augmented generationnot Unleash
  • Similarity search over images, audio or text at scalenot Unleash

Unleash

  • Gradual and progressive feature rolloutsnot Milvus
  • Running A/B/n experiments tied to flagsnot Milvus
  • Self-hosting feature management for compliance needsnot Milvus
  • Enterprise SSO-controlled feature flag governancenot 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

Unleash

  • The Pay-As-You-Go plan is priced per seat, which can get costly for larger teams.
  • Self-hosted Enterprise requires a minimum of 5 seats and an annual contract.
  • Additional API traffic beyond the included quota is billed per million requests.
  • Advanced SLAs and dedicated customer success are reserved for the custom Enterprise tier.

Pricing, plan by plan

Milvus

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

Unleash

Free
  • Pay-As-You-Go$75/month
    • Cloud-hosted
    • 53M API requests/month included
    • Unlimited feature flags, projects and environments
  • Custom Enterprise$undefined/mo
    • Cloud, self-hosted or hybrid
    • Premium support options
    • 99.99% uptime SLA

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 Unleash if

  • You need feature flags.
  • You want to start without paying.
  • You work on web, api, linux.
  • You also want a/b/n testing.
Unleash review

Questions people ask

Is Milvus or Unleash better?
Neither clearly leads. Milvus starts at Free and Unleash at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Milvus or Unleash?
Milvus starts at Free and Unleash at Free.
Does Milvus or Unleash run on more platforms?
Milvus runs on Linux, Mac, Windows, Web. Unleash runs on web, api, linux.
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 Unleash is typically brought in for.
What can Milvus do that Unleash cannot?
Milvus covers Billion-scale vectors, Multiple index types, GPU acceleration, Hybrid search. Unleash covers Feature flags, A/B/n testing, Custom targeting, SDKs.

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
Unleash: What does Unleash cost?

Unleash offers a Pay-As-You-Go cloud plan at $75/seat/month with a 14-day free trial, plus a custom-priced Enterprise plan for self-hosted or hybrid deployments.

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
Unleash: How is usage metered?

The Pay-As-You-Go plan includes 53M API requests per month, with additional traffic billed at $5 per million requests thereafter.

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
Unleash: What does Unleash integrate with, and is there an API?

Unleash provides an API and 25+ official SDKs across languages, along with SSO integrations via SAML 2.0 and OpenID Connect.

Source
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