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Preact vs Weka

Preact logo

Preact

Web Development

3kB alternative to React with the same modern API

From
Free
Rated
-
Full reviewWebsite
Weka logo

Weka

Machine Learning

Collection of machine learning algorithms

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Preact compatibility through preact/compat is good but not total, and some React libraries break in ways that are hard to diagnose; 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: Preact covers 3kB runtime, Weka covers Classification.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Preact and Weka actually diverge.

Attributes where Preact and Weka differ
AttributePreactWeka
Pricing modelOpen source, no licence feeopen-source
PlatformsWebLinux, Mac, Windows
CategoryWeb DevelopmentMachine 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 Preact

  • 3kB runtime
  • preact/compat
  • Same modern API
  • Fast rendering

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.

Preact

  • Embedded widgets that load inside someone else’s page and must stay smallnot Weka
  • Marketing and content sites where JavaScript payload affects Core Web Vitalsnot Weka
  • Applications targeting low-bandwidth or low-powered devicesnot Weka

Weka

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

Where each one falls short

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

Preact

  • Compatibility through preact/compat is good but not total, and some React libraries break in ways that are hard to diagnose
  • Behavioural differences from React exist in edge cases, particularly around event handling
  • A much smaller community, so unusual problems have fewer existing answers than React

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

Preact

Free
  • PreactFree
    • Full library
    • Commercial use permitted
    • No usage limits

Weka

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

Which should you pick?

Choose Preact if

  • You need 3kb runtime.
  • You want to start without paying.
  • You also want preact/compat.
Preact 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 Preact or Weka better?
Neither clearly leads. Preact 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, Preact or Weka?
Preact starts at Free and Weka at Free.
Does Preact or Weka run on more platforms?
Preact runs on Web. Weka runs on Linux, Mac, Windows.
Can I use Preact for free?
Both have a free tier, so you can try either at no cost before committing.
What is Preact best used for?
Preact is most often used for embedded widgets that load inside someone else’s page and must stay small, marketing and content sites where javascript payload affects core web vitals, applications targeting low-bandwidth or low-powered devices. Of those, embedded widgets that load inside someone else’s page and must stay small and marketing and content sites where javascript payload affects core web vitals are not what Weka is typically brought in for.
What can Preact do that Weka cannot?
Preact covers 3kB runtime, preact/compat, Same modern API, Fast rendering. Weka covers Classification, Regression, Clustering, Association rules.

Answered from the vendors’ own pages

Preact: Is Preact free?

Yes, open source under the MIT licence.

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
Preact: Can I use React libraries with Preact?

Most, through the preact/compat layer. Compatibility is good but not complete, so libraries relying on React internals can break.

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
Preact: Why choose Preact over React?

Bundle size, almost always. If payload is not a binding constraint, React’s ecosystem is usually the better trade.

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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