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Developer Tools · head to head

Nixpacks vs Userpilot

Nixpacks logo

Nixpacks

Developer Tools

Build system that turns a source directory into an OCI image, now in maintenance mode

From
Free
Free plan
Yes
Full reviewWebsite
Userpilot logo

Userpilot

Technology

Product analytics and in-app onboarding platform.

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Each has a real cost: Nixpacks the project is in maintenance mode with no commits on the default branch since May 2026 and no release since October 2025, so support for new language versions arrives only if someone forks it.; Userpilot starter tier limited to 2,000 monthly active users; even small-to-medium products may require Growth tier
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Nixpacks and Userpilot actually diverge.

Attributes where Nixpacks and Userpilot differ
AttributeNixpacksUserpilot
Pricing modelOpen source, no licence feesubscription
PlatformsLinux, macOS, CLI, DockerWeb, iOS, Android, API
CategoryDeveloper ToolsTechnology

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 Nixpacks

  • Automatic language detection
  • No Dockerfile required
  • Nix toolchains
  • Configuration escape hatches
  • Docker layer caching

Only in Userpilot

Nothing recorded that Nixpacks does not also cover.

What people use each for

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

Nixpacks

  • Understanding the build behaviour of a platform that adopted Nixpacks before it was frozennot Userpilot
  • Producing container images from a polyglot monorepo where nobody wants to own several Dockerfilesnot Userpilot
  • Reproducing an existing Railway build locally while planning a migration to Railpacknot Userpilot
  • Comparing what a Nix based builder does differently from a buildpack before choosing a successornot Userpilot

Userpilot

  • SaaS companies optimising user onboarding and activationnot Nixpacks
  • Product teams collecting user feedback and identifying churn drivers via session replaynot Nixpacks
  • Customer success teams using in-app guides and contextual helpnot Nixpacks
  • Growth teams orchestrating multi-channel campaigns across email and in-appnot Nixpacks
  • Product managers measuring adoption and engagement across user cohortsnot Nixpacks

Where each one falls short

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

Nixpacks

  • The project is in maintenance mode with no commits on the default branch since May 2026 and no release since October 2025, so support for new language versions arrives only if someone forks it.
  • Build determinism is softer than it appears, because providers pin a nixpkgs archive commit and bumping that archive silently moves compiler and runtime versions underneath a build that looks unchanged.
  • Caching is limited to Docker layers rather than a content addressed graph, so a small change early in the build invalidates everything after it, which is exactly the limitation Railpack was rewritten to fix.
  • Images carry Nix store layers and come out larger than an equivalent tuned Dockerfile or buildpack output, which costs registry storage and slows cold pulls on scale-out.
  • There is no specification, no vendor neutral governance and no third party provider ecosystem, so a single company was able to redirect strategy and leave every downstream user with a frozen build tool.

Userpilot

  • Starter tier limited to 2,000 monthly active users; even small-to-medium products may require Growth tier
  • Large price jump from Starter ($299/mo) to Growth ($849/mo), nearly 3x increase
  • Growth tier scales to 100,000 MAU but does not publish pricing for higher volumes, requiring Enterprise negotiation
  • Session replay and mobile engagement are optional add-ons in Growth tier, not included in base pricing
  • Enterprise pricing not published; custom negotiations required for large-scale deployments

Pricing, plan by plan

Nixpacks

Free
  • NixpacksFree
    • MIT licensed, no usage limits
    • No commercial edition and no support contract
    • In maintenance mode, superseded by Railpack

Userpilot

Free
  • Starter$299/month
    • Up to 2,000 monthly active users
    • In-app engagement
    • User segmentation
  • Growth$849/month (marked 'Most Popular')
    • 2,000 to 100,000 monthly active users
    • All Starter features
    • Advanced product analytics
  • Enterprise$undefined/variable
    • Custom monthly active user levels
    • All Growth features
    • Premium integrations

Which should you pick?

Choose Nixpacks if

  • You need automatic language detection.
  • You want to start without paying.
  • You work on Linux, macOS, CLI, Docker.
  • You also want no dockerfile required.
Nixpacks review

Choose Userpilot if

  • You want to start without paying.
  • You work on Web, iOS, Android, API.
Userpilot review

Questions people ask

Is Nixpacks or Userpilot better?
Neither clearly leads. Nixpacks starts at Free and Userpilot at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Nixpacks or Userpilot?
Nixpacks starts at Free and Userpilot at Free.
Does Nixpacks or Userpilot run on more platforms?
Nixpacks runs on Linux, macOS, CLI, Docker. Userpilot runs on Web, iOS, Android, API.
Can I use Nixpacks for free?
Both have a free tier, so you can try either at no cost before committing.
What is Nixpacks best used for?
Nixpacks is most often used for understanding the build behaviour of a platform that adopted nixpacks before it was frozen, producing container images from a polyglot monorepo where nobody wants to own several dockerfiles, reproducing an existing railway build locally while planning a migration to railpack, comparing what a nix based builder does differently from a buildpack before choosing a successor. Of those, understanding the build behaviour of a platform that adopted nixpacks before it was frozen and producing container images from a polyglot monorepo where nobody wants to own several dockerfiles are not what Userpilot is typically brought in for.
What can Nixpacks do that Userpilot cannot?
Nixpacks covers Automatic language detection, No Dockerfile required, Nix toolchains, Configuration escape hatches.

Answered from the vendors’ own pages

Nixpacks: Should I start a new project on Nixpacks?

No. The documentation and README both say it is in maintenance mode and recommend Railpack. Choose Railpack, Cloud Native Buildpacks or a Dockerfile instead.

Userpilot: What is included in the free trial?

Userpilot offers a free 14-day trial without requiring a credit card, providing full access to the Starter tier features.

Source
Nixpacks: Will my existing Nixpacks builds stop working?

Not immediately. Pinned nixpkgs archives keep resolving, so builds continue. What you lose is support for new runtime major versions and any fix for a provider bug.

Userpilot: Does Userpilot include session replay?

Session replay is available in the Growth tier as an optional add-on for watching real user sessions and identifying friction points.

Source
Nixpacks: What replaces it?

Railpack, also from Railway and also MIT licensed, rebuilt as a BuildKit custom frontend for finer grained caching and parallel steps.

Userpilot: What integrations does Userpilot support?

Userpilot integrates with HubSpot, Salesforce, Segment, Google Analytics, Amplitude, Mixpanel, Heap, Zendesk, Intercom and Google Tag Manager. Additional integrations can be requested.

Source
Nixpacks: Is it still open source?

Yes, MIT, and the repository is not archived. Being open source does not help much when nobody is merging provider updates.

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