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AI · head to head

Modal vs PromptLayer

Modal logo

Modal

AI

Cloud functions for AI and ML

From
Free
Rated
-
Full reviewWebsite
PromptLayer logo

PromptLayer

AI

Collaboration platform for prompt management, evaluation, and observability

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: 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; PromptLayer the free plan is capped at only 2,500 requests per month, quite limited for active production use.
  • They diverge on capability: Modal covers Serverless GPUs, PromptLayer covers Visual prompt management.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Modal and PromptLayer actually diverge.

Attributes where Modal and PromptLayer differ
AttributeModalPromptLayer
Pricing modelusage-basedfreemium
PlatformsCloud, Apiweb, api
Founded2021Unknown

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (AI).

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 Modal

  • Serverless GPUs
  • Python functions
  • Auto-scaling
  • Fast cold starts
  • Python SDK
  • GitHub Actions
  • Cloud storage
  • Cloud support

Only in PromptLayer

  • Visual prompt management
  • Agent observability
  • Evaluations
  • Version control
  • Cost and latency monitoring
  • Agent workflow tracing

What people use each for

The jobs each tool is most often brought in to do.

Modal

  • Running serverless GPU workloads for model inference and trainingnot PromptLayer
  • Executing Python functions on cloud compute without managing serversnot PromptLayer

PromptLayer

  • Versioning and deploying prompts without code redeploysnot Modal
  • Running evaluations with human review before production releasenot Modal
  • Tracing multi-step agent workflows for debuggingnot Modal
  • Monitoring LLM cost and latency by featurenot Modal

Where each one falls short

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

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

PromptLayer

  • The free plan is capped at only 2,500 requests per month, quite limited for active production use.
  • The Team plan jumps to $500/month, a large step up from the $49/month Pro plan.
  • Overage transaction fees apply on top of subscription costs, which can make total spend less predictable.
  • Enterprise-grade features like HIPAA BAAs and custom deployment require contacting sales.

Pricing, plan by plan

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

PromptLayer

Free
  • FreeFree
    • 5 users
    • 2,500 requests/month
    • 1 workspace
  • Pro$49/month
    • Unlimited playgrounds and workspaces
    • 150MB datasets
    • Pay-as-you-go overage at $0.003/transaction
  • Team$500/month
    • 25 users
    • 100k+ monthly requests
    • Webhooks
  • Enterprise$undefined/mo
    • Custom limits
    • Role-based access controls
    • HIPAA with BAA

Which should you pick?

Choose Modal if

  • You need serverless gpus.
  • You want to start without paying.
  • You work on Cloud, Api.
  • You also want python functions.
Modal review

Choose PromptLayer if

  • You need visual prompt management.
  • You want to start without paying.
  • You work on web, api.
  • You also want agent observability.
PromptLayer review

Questions people ask

Is Modal or PromptLayer better?
Neither clearly leads. Modal starts at Free and PromptLayer at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Modal or PromptLayer?
Modal starts at Free and PromptLayer at Free.
Does Modal or PromptLayer run on more platforms?
Modal runs on Cloud, Api. PromptLayer runs on web, api.
Can I use Modal for free?
Both have a free tier, so you can try either at no cost before committing.
What is Modal best used for?
Modal is most often used for running serverless gpu workloads for model inference and training, executing python functions on cloud compute without managing servers. Of those, running serverless gpu workloads for model inference and training and executing python functions on cloud compute without managing servers are not what PromptLayer is typically brought in for.
What can Modal do that PromptLayer cannot?
Modal covers Serverless GPUs, Python functions, Auto-scaling, Fast cold starts. PromptLayer covers Visual prompt management, Agent observability, Evaluations, Version control.

Answered from the vendors’ own pages

Modal: 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.

Source
PromptLayer: What does PromptLayer cost?

PromptLayer has a free plan, a Pro plan at $49/month, a Team plan at $500/month, and custom Enterprise pricing, with additional usage billed per transaction beyond plan limits.

Source
Modal: Is there a free tier?

Yes, Starter plan is free plus 30 USD/month in compute credits included monthly for new users.

Source
PromptLayer: Is there a free plan, and what are its limits?

The Free plan includes 5 users, 2,500 requests per month, 1 workspace, 250 monthly eval cell executions, and datasets up to 10MB.

Source
Modal: What are the seat limits?

Starter plan includes 3 seats; Team plan provides unlimited seats; Enterprise tier has custom seat allocations.

Source
PromptLayer: How is usage metered beyond the plan limits?

Additional usage is charged per transaction for requests, agent runs, and evaluation cell runs, at $0.003/transaction on Pro and $0.002/transaction on Team.

Source
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