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Developer Tools · head to head

Nixpacks vs Spacelift

Nixpacks logo

Nixpacks

Developer Tools

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

From
Free
Rated
-
Full reviewWebsite
Spacelift logo

Spacelift

Developer Tools

Infrastructure-as-code orchestration for Terraform, OpenTofu, Pulumi and Kubernetes

From
Free
Rated
-
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.; Spacelift users are unlimited and private workers are metered, so deployment concurrency rather than headcount drives the bill, which inverts how most engineering budgets are built and is easy to under-forecast.
  • They diverge on capability: Nixpacks covers Automatic language detection, Spacelift covers Multi-tool orchestration.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Nixpacks and Spacelift actually diverge.

Attributes where Nixpacks and Spacelift differ
AttributeNixpacksSpacelift
Pricing modelOpen source, no licence feeBy private worker and tier, not by user
PlatformsLinux, macOS, CLI, DockerWeb, Self-hosted, Cloud

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Developer Tools).

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 Spacelift

  • Multi-tool orchestration
  • Policy as code
  • Private workers
  • Spaces
  • Blueprints
  • Drift detection

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 Spacelift
  • Producing container images from a polyglot monorepo where nobody wants to own several Dockerfilesnot Spacelift
  • Reproducing an existing Railway build locally while planning a migration to Railpacknot Spacelift
  • Comparing what a Nix based builder does differently from a buildpack before choosing a successornot Spacelift

Spacelift

  • Platform teams running infrastructure changes through approval gates rather than through application CInot Nixpacks
  • Organisations standardising Terraform and OpenTofu across many teams with policy enforcementnot Nixpacks
  • Estates needing private runners so cloud credentials never leave the networknot Nixpacks
  • Teams wanting drift detection and reconciliation rather than plan-time checks alonenot 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.

Spacelift

  • Users are unlimited and private workers are metered, so deployment concurrency rather than headcount drives the bill, which inverts how most engineering budgets are built and is easy to under-forecast.
  • There is no affordable paid entry point. The free tier stops at two users and the next tier is a five-figure commitment with nothing in between.
  • Three of the five tiers are quote-only, so a shortlist cannot be costed without entering a sales process with each vendor on it.
  • The self-hosted build lags the hosted one, has no public worker pool and lacks the Azure and Google Cloud integrations available in the SaaS product, with OIDC federation offered as the workaround.
  • Stacks, Rego policies, Blueprints, Spaces and Spacelift-managed state are proprietary constructs, so leaving means rebuilding the orchestration layer rather than pointing it at a different runner.

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

Spacelift

Free
  • FreeFree
    • Two users
    • Public workers only
    • No private workers
  • Starter Plus$undefined/year
    • Unlimited users
    • Two public workers
    • One to two private workers
  • Business$undefined/year
    • Unlimited users
    • Three private workers
    • Quoted
  • Enterprise$undefined/year
    • Unlimited users
    • Five to thirty private workers
    • Self-hosted option

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 Spacelift if

  • You need multi-tool orchestration.
  • You want to start without paying.
  • You work on Web, Self-hosted, Cloud.
  • You also want policy as code.
Spacelift review

Questions people ask

Is Nixpacks or Spacelift better?
Neither clearly leads. Nixpacks starts at Free and Spacelift at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Nixpacks or Spacelift?
Nixpacks starts at Free and Spacelift at Free.
Does Nixpacks or Spacelift run on more platforms?
Nixpacks runs on Linux, macOS, CLI, Docker. Spacelift runs on Web, Self-hosted, Cloud.
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 Spacelift is typically brought in for.
What can Nixpacks do that Spacelift cannot?
Nixpacks covers Automatic language detection, No Dockerfile required, Nix toolchains, Configuration escape hatches. Spacelift covers Multi-tool orchestration, Policy as code, Private workers, Spaces.

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.

Spacelift: How is Spacelift priced?

By tier and by private worker count rather than per user. Users are unlimited on every paid plan. The published figure on the pricing page carries no period label, and the FAQ describes the tier as an annual subscription, so confirm the period in writing.

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.

Spacelift: Does it support OpenTofu?

Yes, and Spacelift sponsors the OpenTofu project, which is a substantive hedge for anyone avoiding Terraform under the Business Source Licence.

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.

Spacelift: Is there a self-hosted version?

Yes, described as carrying Enterprise functionality, but it is priced on request and lags the hosted product on cloud integrations.

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.

Spacelift: Why not just use the CI system we already have?

That is the real comparison. General purpose CI handles state, drift, approval gates and concurrency control for infrastructure poorly, and whether that is worth a five-figure floor depends on how much infrastructure change your organisation actually ships.

Spacelift: What happens to our pipelines if we leave?

They do not port. Rego policies, Blueprints, Spaces and managed state are Spacelift constructs and the orchestration has to be rebuilt elsewhere.

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