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Developer Tools · head to head

GNAT Pro vs Preact

GNAT Pro logo

GNAT Pro

Developer Tools

Software development environments and toolchains for Ada, C/C++ and Rust

From
On request
Free plan
No
Full reviewWebsite
Preact logo

Preact

Web Development

3kB alternative to React with the same modern API

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Only Preact has a free tier, so it costs nothing to try first.
  • Each has a real cost: GNAT Pro no pricing published on website; requires contacting AdaCore directly for quotes; Preact compatibility through preact/compat is good but not total, and some React libraries break in ways that are hard to diagnose
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which GNAT Pro and Preact actually diverge.

Attributes where GNAT Pro and Preact differ
AttributeGNAT ProPreact
Starting priceOn requestFree
Pricing modelquoteOpen source, no licence fee
Free tierNoYes
CategoryDeveloper ToolsWeb Development

Identical on both: platforms (Web), 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 GNAT Pro

Nothing recorded that Preact does not also cover.

Only in Preact

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

What people use each for

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

GNAT Pro

  • Building certified avionics software meeting DO-178B/C standardsnot Preact
  • Developing automotive embedded systems with ISO-26262 compliancenot Preact
  • Integrating Ada, C/C++, and Rust components in single codebasenot Preact
  • Managing software supply chain vulnerabilities and SBOMsnot Preact
  • Supporting long-lived software systems spanning decadesnot Preact

Preact

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

Where each one falls short

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

GNAT Pro

  • No pricing published on website; requires contacting AdaCore directly for quotes
  • Vendor indicates per-user, per-year subscription model but does not disclose specific costs

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

Pricing, plan by plan

GNAT Pro

On request

No published plan breakdown. See the GNAT Pro review.

Preact

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

Which should you pick?

Choose GNAT Pro if

Nothing in the data separates GNAT Pro from Preact on the points above - pick on price and on how each one feels to use.

GNAT Pro review

Choose Preact if

  • You need 3kb runtime.
  • You want to start without paying.
  • You also want preact/compat.
Preact review

Questions people ask

Is GNAT Pro or Preact better?
Neither clearly leads. GNAT Pro starts at On request and Preact at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, GNAT Pro or Preact?
Preact has a free tier; the other does not. Paid plans start at On request for GNAT Pro and Free for Preact.
Does GNAT Pro or Preact run on more platforms?
Both run on Web, so platform support will not decide this one for you.
Can I use Preact for free?
Yes. Preact has a free tier, so you can try it without paying. GNAT Pro starts at On request.
What is GNAT Pro best used for?
GNAT Pro is most often used for building certified avionics software meeting do-178b/c standards, developing automotive embedded systems with iso-26262 compliance, integrating ada, c/c++, and rust components in single codebase, managing software supply chain vulnerabilities and sboms. Of those, building certified avionics software meeting do-178b/c standards and developing automotive embedded systems with iso-26262 compliance are not what Preact is typically brought in for.
What can GNAT Pro do that Preact cannot?
Preact covers 3kB runtime, preact/compat, Same modern API, Fast rendering.

Answered from the vendors’ own pages

GNAT Pro: How much does GNAT Pro cost?

GNAT Pro pricing is not published on the website. Customers must request a pricing quote by contacting AdaCore directly or speaking with a GNAT Pro expert.

Source
Preact: Is Preact free?

Yes, open source under the MIT licence.

GNAT Pro: What is GNAT Pro licensing model?

GNAT Pro is sold on a per-user, per-year basis with no license locks. Customers can request pricing for their specific needs.

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.

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.

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