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Nix vs Preact

Nix logo

Nix

Developer Tools

Purely functional package manager and the NixOS distribution built on it, for byte-reproducible environments

From
Free
Free plan
Yes
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

  • Each has a real cost: Nix the Nix language is lazy, dynamically typed and poorly documented, and its error messages frequently point at the wrong expression, so debugging a failing build is a skill that takes months rather than days to acquire.; Preact compatibility through preact/compat is good but not total, and some React libraries break in ways that are hard to diagnose
  • They diverge on capability: Nix covers Content-addressed store, Preact covers 3kB runtime.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Nix and Preact actually diverge.

Attributes where Nix and Preact differ
AttributeNixPreact
PlatformsLinux, macOS, Windows (via WSL)Web
CategoryDeveloper ToolsWeb Development

Identical on both: starting price (Free), pricing model (Open source, no licence fee), 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 Nix

  • Content-addressed store
  • Declarative system configuration
  • Atomic upgrades and rollback
  • nix develop shells
  • Flakes
  • Nixpkgs
  • Binary caches
  • Home Manager

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.

Nix

  • A team that wants every developer and CI runner to use byte-identical toolchains without shipping a container for local worknot Preact
  • Reproducing a research computation or a build years later from a pinned commit rather than a written recipenot Preact
  • Managing a fleet of Linux servers declaratively with atomic rollback if a deployment breaks a servicenot Preact
  • Building minimal container images from precise dependency closures instead of a base image plus a package managernot Preact

Preact

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

Where each one falls short

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

Nix

  • The Nix language is lazy, dynamically typed and poorly documented, and its error messages frequently point at the wrong expression, so debugging a failing build is a skill that takes months rather than days to acquire.
  • Flakes are the way essentially everyone uses Nix in 2026 and are still formally an experimental feature behind a flag, meaning tutorials, official documentation and real practice disagree with each other constantly.
  • Anything that expects a conventional Linux filesystem layout breaks: prebuilt binaries, language package managers that download their own toolchains, and proprietary vendor installers all need patching or an FHS-compatible wrapper.
  • Project governance has been publicly fractious, producing the Lix fork and the separately funded Determinate Systems distribution, so a new adopter now has to choose which Nix before they can start.
  • The /nix/store grows without bound until you garbage collect, and on a developer laptop with several pinned nixpkgs revisions it routinely reaches tens of gigabytes.

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

Nix

Free
  • Nix and NixOSFree
    • LGPL-2.1 licensed, no commercial tier
    • Public binary cache at cache.nixos.org
    • Community support via forum, Matrix and GitHub

Preact

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

Which should you pick?

Choose Nix if

  • You need content-addressed store.
  • You want to start without paying.
  • You work on Linux, macOS, Windows (via WSL).
  • You also want declarative system configuration.
Nix 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 Nix or Preact better?
Neither clearly leads. Nix starts at Free and Preact at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Nix or Preact?
Nix starts at Free and Preact at Free.
Does Nix or Preact run on more platforms?
Nix runs on Linux, macOS, Windows (via WSL). Preact runs on Web.
Can I use Nix for free?
Both have a free tier, so you can try either at no cost before committing.
What is Nix best used for?
Nix is most often used for a team that wants every developer and ci runner to use byte-identical toolchains without shipping a container for local work, reproducing a research computation or a build years later from a pinned commit rather than a written recipe, managing a fleet of linux servers declaratively with atomic rollback if a deployment breaks a service, building minimal container images from precise dependency closures instead of a base image plus a package manager. Of those, a team that wants every developer and ci runner to use byte-identical toolchains without shipping a container for local work and reproducing a research computation or a build years later from a pinned commit rather than a written recipe are not what Preact is typically brought in for.
What can Nix do that Preact cannot?
Nix covers Content-addressed store, Declarative system configuration, Atomic upgrades and rollback, nix develop shells. Preact covers 3kB runtime, preact/compat, Same modern API, Fast rendering.

Answered from the vendors’ own pages

Nix: Do I have to run NixOS to use Nix?

No. The package manager runs fine on any Linux distribution and on macOS, and most teams start there with development shells rather than converting their servers.

Preact: Is Preact free?

Yes, open source under the MIT licence.

Nix: Is Nix a replacement for Docker?

It solves an adjacent problem. Nix reproduces the contents of an environment exactly; Docker distributes an image. Many teams use Nix to build the image.

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.

Nix: Are flakes safe to use in production?

They are used in production widely and are stable in practice, but they remain officially experimental, which means the interface can still change and documentation is split.

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.

Nix: What is Lix and should I care?

Lix is a community fork of the Nix implementation created after governance disputes. It is largely compatible; the practical impact is that you must decide which implementation your team standardises on.

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