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Cybersecurity · head to head

Arnica vs Nixpacks

Arnica logo

Arnica

Cybersecurity

AI-native application security platform detecting and fixing vulnerabilities across the SDLC

From
Free
Free plan
Yes
Full reviewWebsite
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

The short version

  • Each has a real cost: Arnica per-identity pricing ($25-$50/person/year) requires tracking active developers; 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.
  • They diverge on capability: Arnica covers AI SAST, Nixpacks covers Automatic language detection.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Arnica and Nixpacks actually diverge.

Attributes where Arnica and Nixpacks differ
AttributeArnicaNixpacks
Pricing modelPer-identity subscription with annual discountOpen source, no licence fee
PlatformsWeb, GitHub, IDELinux, macOS, CLI, Docker
CategoryCybersecurityDeveloper Tools

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 Arnica

  • AI SAST
  • Software Composition Analysis
  • Secrets detection
  • IaC scanning
  • Container scanning
  • SBOM generation
  • Agentic rules
  • Pipelineless integration

Only in Nixpacks

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

What people use each for

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

Arnica

  • Detecting AI-generated vulnerabilities in Copilot and Cursor suggestionsnot Nixpacks
  • Finding hardcoded secrets before they reach productionnot Nixpacks
  • Mapping container vulnerabilities back to source codenot Nixpacks
  • Generating SBOM for supply chain compliance requirementsnot Nixpacks
  • Scanning infrastructure-as-code for misconfiguration risksnot Nixpacks

Nixpacks

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

Where each one falls short

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

Arnica

  • Per-identity pricing ($25-$50/person/year) requires tracking active developers
  • Overage identity tracking via 90-day PR activity can be unpredictable
  • Free plan limited to weekly updates, requiring upgrade for real-time scanning
  • Advanced add-ons (Image Scanning, AI SAST, Agentic Rules Enforcer) pricing not published
  • On-premises deployment limited to Enterprise tier

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.

Pricing, plan by plan

Arnica

Free
  • FreeFree
    • No credit card required
    • 14-day trial available
    • Weekly risk identification updates
  • Core Business$360/year
    • Monthly billing option at $30/identity/month
    • Annual billing at $25/identity/month (17% discount)
    • Real-time risk scanning and notifications
  • Core Enterprise$720/year
    • Monthly billing option at $60/identity/month
    • Annual billing at $50/identity/month (17% discount)
    • All Core Business features

Nixpacks

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

Which should you pick?

Choose Arnica if

  • You need ai sast.
  • You want to start without paying.
  • You work on Web, GitHub, IDE.
  • You also want software composition analysis.
Arnica review

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

Questions people ask

Is Arnica or Nixpacks better?
Neither clearly leads. Arnica starts at Free and Nixpacks at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Arnica or Nixpacks?
Arnica starts at Free and Nixpacks at Free.
Does Arnica or Nixpacks run on more platforms?
Arnica runs on Web, GitHub, IDE. Nixpacks runs on Linux, macOS, CLI, Docker.
Can I use Arnica for free?
Both have a free tier, so you can try either at no cost before committing.
What is Arnica best used for?
Arnica is most often used for detecting ai-generated vulnerabilities in copilot and cursor suggestions, finding hardcoded secrets before they reach production, mapping container vulnerabilities back to source code, generating sbom for supply chain compliance requirements. Of those, detecting ai-generated vulnerabilities in copilot and cursor suggestions and finding hardcoded secrets before they reach production are not what Nixpacks is typically brought in for.
What can Arnica do that Nixpacks cannot?
Arnica covers AI SAST, Software Composition Analysis, Secrets detection, IaC scanning. Nixpacks covers Automatic language detection, No Dockerfile required, Nix toolchains, Configuration escape hatches.

Answered from the vendors’ own pages

Arnica: How are identities defined in Arnica pricing?

Identities are any users and other contributing entities that contributed code and/or had PR activity during the last 90 days. This ensures billing matches active developers.

Source
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.

Arnica: What is the annual discount?

Annual prepayment offers approximately 17% savings versus monthly billing. Core Business annual is $300/identity versus $360 for monthly.

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.

Arnica: Can I cancel or downgrade Arnica anytime?

Yes. Subscriptions can be cancelled or downgraded at any time. Overage identities receive automatic protection with true-up invoicing.

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.

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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