Softwr

Machine Learning · head to head

Comet ML vs Replika

Comet ML logo

Comet ML

Machine Learning

Platform for tracking, comparing, and optimizing ML experiments

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: Comet ML the free cloud tier caps data at 25,000 spans a month with 60 day retention; Replika pricing not published on main website or pricing page
  • They diverge on capability: Comet ML covers Experiment tracking, Replika covers Conversational AI.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Comet ML and Replika actually diverge.

Attributes where Comet ML and Replika differ
AttributeComet MLReplika
PlatformsWeb, Linux, Mac, WindowsIos, 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 Comet ML

  • Experiment tracking
  • Code versioning
  • Model registry
  • Hyperparameter optimization
  • Production monitoring
  • PyTorch
  • TensorFlow
  • Keras

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.

Comet ML

  • LLM observability and monitoringnot Replika
  • AI agent testing and debuggingnot Replika
  • Experiment tracking for machine learningnot Replika
  • Model registry and version managementnot Replika
  • ML model training monitoringnot Replika

Replika

  • ai tools managementnot Comet ML
  • Workflow automationnot Comet ML
  • Reportingnot Comet ML

Where each one falls short

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

Comet ML

  • The free cloud tier caps data at 25,000 spans a month with 60 day retention
  • Retention stays at 60 days even on the paid Pro plan, and extending it is a $29 per 100k spans add on
  • Overage on Pro is $5 per additional 100,000 spans
  • The free MLOps tier is a single user with 100 GB of storage and training hours governed by a fair usage policy
  • Pro MLOps is $19 per user per month and caps the team at 10 users

Replika

  • Pricing not published on main website or pricing page

Pricing, plan by plan

Comet ML

Free
  • Free CloudFree
    • Up to 10 team members
    • 25,000 spans per month
    • 60-day data retention
  • Pro Cloud$19/month
    • Up to 50 team members
    • 100,000 spans per month
    • 60-day data retention
  • MLOps FreeFree
    • 1 user with fair usage policy
    • Experiment tracking
    • Dataset management
  • MLOps Pro$19/user/month
    • Up to 10 users
    • 1,500 training hours included
    • 500GB storage included

Replika

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

Which should you pick?

Choose Comet ML if

  • You need experiment tracking.
  • You want to start without paying.
  • You work on Web, Linux, Mac, Windows.
  • You also want code versioning.
Comet ML 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 Comet ML or Replika better?
Neither clearly leads. Comet ML 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, Comet ML or Replika?
Comet ML starts at Free and Replika at Free.
Does Comet ML or Replika run on more platforms?
Comet ML runs on Web, Linux, Mac, Windows. Replika runs on Ios, Android, Web.
Can I use Comet ML for free?
Both have a free tier, so you can try either at no cost before committing.
What is Comet ML best used for?
Comet ML is most often used for llm observability and monitoring, ai agent testing and debugging, experiment tracking for machine learning, model registry and version management. Of those, llm observability and monitoring and ai agent testing and debugging are not what Replika is typically brought in for.
What can Comet ML do that Replika cannot?
Comet ML covers Experiment tracking, Code versioning, Model registry, Hyperparameter optimization. Replika covers Conversational AI, Memory, Emotional support, Voice calls. Both handle Web support.

Answered from the vendors’ own pages

Comet ML: Does Comet.ml offer a free plan?

Yes, Comet.ml offers free tiers for both Opik (cloud observability) and MLOps platforms. Free Cloud Opik includes up to 10 team members and 25,000 spans/month. Free MLOps tier is limited to 1 user.

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
Comet ML: How many team members can use the free Comet.ml tier?

Free Cloud supports up to 10 team members. The Pro Cloud plan supports up to 50 team members at $19/month.

Source
Comet ML: What is a span in Comet.ml pricing?

A span represents a single tracked operation such as model requests or function calls. Free Cloud tier includes 25,000 spans per month.

Source
Comet ML: Does Comet.ml offer academic pricing?

Yes, a free Pro plan is available for academic users; verification is required via signup.

Source
Share

Related pages

More on Comet ML

More on Replika

Keep looking

Other head to heads