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AI · head to head

PromptLayer vs Weka

PromptLayer logo

PromptLayer

AI

Collaboration platform for prompt management, evaluation, and observability

From
Free
Free plan
Yes
Full reviewWebsite
Weka logo

Weka

Machine Learning

Collection of machine learning algorithms

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: PromptLayer the free plan is capped at only 2,500 requests per month, quite limited for active production use.; Weka the package management system needs an internet connection to download and install packages, so an air-gapped install gets only the core distribution
  • They diverge on capability: PromptLayer covers Visual prompt management, Weka covers Classification.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which PromptLayer and Weka actually diverge.

Attributes where PromptLayer and Weka differ
AttributePromptLayerWeka
Pricing modelfreemiumopen-source
Platformsweb, apiLinux, Mac, Windows
CategoryAIMachine Learning
FoundedUnknown1993

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 PromptLayer

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

Only in Weka

  • Classification
  • Regression
  • Clustering
  • Association rules
  • Feature selection
  • Java
  • R
  • Python

What people use each for

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

PromptLayer

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

Weka

  • Teaching and exploring classic machine learning algorithms through a GUInot PromptLayer
  • Running data mining experiments and preprocessing without writing codenot PromptLayer

Where each one falls short

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

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.

Weka

  • The package management system needs an internet connection to download and install packages, so an air-gapped install gets only the core distribution
  • Weka is split into a stable 3.8 branch that receives only bug fixes and compatibility-safe upgrades and a 3.9 development branch that may receive features that break compatibility
  • Weka requires a 64-bit Java VM; the bundled installers ship Bellsoft OpenJDK 25 per platform and architecture

Pricing, plan by plan

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

Weka

Free
  • Open SourceFree
    • All ML algorithms
    • GUI and CLI
    • Java API

Which should you pick?

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

Choose Weka if

  • You need classification.
  • You want to start without paying.
  • You work on Linux, Mac, Windows.
  • You also want regression.
Weka review

Questions people ask

Is PromptLayer or Weka better?
Neither clearly leads. PromptLayer starts at Free and Weka at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, PromptLayer or Weka?
PromptLayer starts at Free and Weka at Free.
Does PromptLayer or Weka run on more platforms?
PromptLayer runs on web, api. Weka runs on Linux, Mac, Windows.
Can I use PromptLayer for free?
Both have a free tier, so you can try either at no cost before committing.
What is PromptLayer best used for?
PromptLayer is most often used for versioning and deploying prompts without code redeploys, running evaluations with human review before production release, tracing multi-step agent workflows for debugging, monitoring llm cost and latency by feature. Of those, versioning and deploying prompts without code redeploys and running evaluations with human review before production release are not what Weka is typically brought in for.
What can PromptLayer do that Weka cannot?
PromptLayer covers Visual prompt management, Agent observability, Evaluations, Version control. Weka covers Classification, Regression, Clustering, Association rules.

Answered from the vendors’ own pages

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
Weka: What is the cost of Weka software?

Weka is provided at no cost as open-source software released under the GNU General Public License, making it freely available for download and use.

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
Weka: Are there commercial licensing options available?

Yes, the project offers information about commercial licenses for organizations requiring non-GPL terms, which can be found in their commercial applications documentation.

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
Weka: What support resources are available to users?

Multiple support avenues exist including comprehensive documentation, frequently asked questions, dedicated help resources, and access to courses for learning the platform.

Source
Weka: Is source code access provided?

Yes, developers have full access to source code through the Git repository, along with development documentation and code credits for contributors.

Source
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