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Machine Learning · head to head

Milvus vs Replika

Milvus logo

Milvus

Machine Learning

Open-source vector database for scalable similarity search

From
Free
Free plan
Yes
Full reviewWebsite
Replika logo

Replika

AI

AI companion for meaningful conversations

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: Milvus vector dimensions are capped at 32,768; Replika pricing not published on main website or pricing page
  • They diverge on capability: Milvus covers Billion-scale vectors, Replika covers Conversational AI.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Milvus and Replika actually diverge.

Attributes where Milvus and Replika differ
AttributeMilvusReplika
PlatformsLinux, Mac, Windows, WebIos, Android, Web
CategoryMachine LearningAI
Founded20172016

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 Replika

  • Conversational AI
  • Memory
  • Emotional support
  • Voice calls
  • AR features
  • Mobile apps
  • Ios support
  • Android support

Both cover

  • Web support

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

Replika

  • ai tools managementnot Milvus
  • Workflow automationnot Milvus
  • Reportingnot 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

Replika

  • Pricing not published on main website or pricing page

Pricing, plan by plan

Milvus

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

Replika

Free
  • FreeFree
    • Basic conversations
    • Memory
  • Pro$7.99/month
    • All features
    • Voice calls
    • AR

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 Replika if

  • You need conversational ai.
  • You want to start without paying.
  • You work on Ios, Android, Web.
  • You also want memory.
Replika review

Questions people ask

Is Milvus or Replika better?
Neither clearly leads. Milvus starts at Free and Replika at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Milvus or Replika?
Milvus starts at Free and Replika at Free.
Does Milvus or Replika run on more platforms?
Milvus runs on Linux, Mac, Windows, Web. Replika runs on Ios, Android, Web.
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 Replika is typically brought in for.
What can Milvus do that Replika cannot?
Milvus covers Billion-scale vectors, Multiple index types, GPU acceleration, Hybrid search. Replika covers Conversational AI, Memory, Emotional support, Voice calls. Both handle Web support.

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
Replika: How much does Replika cost?

Replika does not publish specific pricing information on its website. The app directs users to get the application, suggesting a subscription model exists, but pricing tiers and costs are not disclosed on the public site.

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
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
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