Machine Learning · head to head
Comet ML vs Modal
Comet ML
Machine Learning
Platform for tracking, comparing, and optimizing ML experiments
- From
- Free
- Free plan
- Yes
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; Modal the Team plan carries a $250 monthly base fee and returns only $100 of that as free credits, so $150 is a flat charge before any compute
- They diverge on capability: Comet ML covers Experiment tracking, Modal covers Serverless GPUs.
- Prices and features above were last checked on 30 August 2026.
Where they differ
Only the attributes on which Comet ML and Modal actually diverge.
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 Comet ML
- Experiment tracking
- Code versioning
- Model registry
- Hyperparameter optimization
- Production monitoring
- PyTorch
- TensorFlow
- Keras
Only in Modal
- Serverless GPUs
- Python functions
- Auto-scaling
- Fast cold starts
- Python SDK
- GitHub Actions
- Cloud storage
- Cloud support
What people use each for
The jobs each tool is most often brought in to do.
Comet ML
- LLM observability and monitoringnot Modal
- AI agent testing and debuggingnot Modal
- Experiment tracking for machine learningnot Modal
- Model registry and version managementnot Modal
- ML model training monitoringnot Modal
Modal
- Running serverless GPU workloads for model inference and trainingnot Comet ML
- Executing Python functions on cloud compute without managing serversnot 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
Modal
- The Team plan carries a $250 monthly base fee and returns only $100 of that as free credits, so $150 is a flat charge before any compute
- Compute is billed per second across separate GPU and CPU meters, so total cost depends on execution time rather than any fixed rate
- The Starter plan's $30 monthly free credit is the only allowance below the paid base fee
- Enterprise volume discounts are custom and unpublished
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
Modal
Free- StarterFree
- 3 seats
- 100 containers
- 10 GPU concurrency
- Team$250/month
- Unlimited seats
- 5,000 containers
- 50 GPU concurrency
- Enterprise$null/custom
- Custom seats, containers, and GPU concurrency
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.
Choose Modal if
- You need serverless gpus.
- You want to start without paying.
- You work on Cloud, Api.
- You also want python functions.
Questions people ask
- Is Comet ML or Modal better?
- Neither clearly leads. Comet ML starts at Free and Modal at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Comet ML or Modal?
- Comet ML starts at Free and Modal at Free.
- Does Comet ML or Modal run on more platforms?
- Comet ML runs on Web, Linux, Mac, Windows. Modal runs on Cloud, Api.
- 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 Modal is typically brought in for.
- What can Comet ML do that Modal cannot?
- Comet ML covers Experiment tracking, Code versioning, Model registry, Hyperparameter optimization. Modal covers Serverless GPUs, Python functions, Auto-scaling, Fast cold starts.
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.
SourceModal: How much does Modal cost?
Modal uses pay-as-you-go pricing with Team plan at 250 USD/month base. Starter includes 30 USD/month free credits; Team includes 100 USD/month free credits. Compute charges per second for CPU cores, memory, and GPU instances.
SourceComet 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.
SourceModal: Is there a free tier?
Yes, Starter plan is free plus 30 USD/month in compute credits included monthly for new users.
SourceComet 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.
SourceModal: What are the seat limits?
Starter plan includes 3 seats; Team plan provides unlimited seats; Enterprise tier has custom seat allocations.
SourceComet ML: Does Comet.ml offer academic pricing?
Yes, a free Pro plan is available for academic users; verification is required via signup.
SourceRelated pages
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