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Cloud · head to head

Infracost vs Preact

Infracost logo

Infracost

Cloud

Cloud cost estimates in pull requests, with governance in the paid tier

From
Free
Rated
-
Full reviewWebsite
Preact logo

Preact

Web Development

3kB alternative to React with the same modern API

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Infracost usage-based resources such as object storage, serverless functions and data transfer have no cost without monthly usage figures supplied by hand, and the documentation warns plainly that engineers otherwise read them as free.; 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: Infracost covers Pull request cost diffs, Preact covers 3kB runtime.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Infracost and Preact actually diverge.

Attributes where Infracost and Preact differ
AttributeInfracostPreact
Pricing modelFree open source tool, then per month by run volumeOpen source, no licence fee
PlatformsWeb, macOS, Linux, Windows, DockerWeb
CategoryCloudWeb Development

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 Infracost

  • Pull request cost diffs
  • Multi-format parsing
  • Apache-2.0 CLI
  • FinOps policies
  • Automated remediation
  • IDE integration

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.

Infracost

  • Teams that want an expensive infrastructure change questioned at review rather than discovered on an invoicenot Preact
  • Platform groups enforcing tagging so cloud spend can be attributed to a team at allnot Preact
  • Organisations adopting FinOps practice without buying a full cloud management platformnot Preact
  • Engineers who want a cost figure in the editor while writing the Terraformnot Preact

Preact

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

Where each one falls short

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

Infracost

  • Usage-based resources such as object storage, serverless functions and data transfer have no cost without monthly usage figures supplied by hand, and the documentation warns plainly that engineers otherwise read them as free.
  • Splitting production from non-production usage assumptions is not supported in the free usage file, which the docs attribute to a missing project filter, so that separation requires the paid product.
  • The step from 250 to 1,000 dollars a month is large and the Cloud tier includes only ten admin seats, with developer seats charged at a figure that is not published, so the cost for a large organisation cannot be computed from the pricing page.
  • Estimates are list price. Negotiated agreements, committed use discounts and reserved instance economics require SKU-level overrides available only on Enterprise, so the number in the pull request is not the number on the bill.
  • The share of the product covered by the Apache-2.0 licence is shrinking. Checks, automated fixes, policies and agent integrations are all hosted-only, so the permissive licence increasingly protects the estimation engine rather than the product.

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

Infracost

Free
  • FreeFree
    • 1,000 runs a month
    • Terraform, CloudFormation and CDK estimates
    • Community support
  • Starter$250/month
    • 10,000 runs a month
    • Email support
  • Cloud$1000/month
    • Ten admin seats, developer seats charged separately
    • FinOps policies and cost guardrails
    • Dashboards and audit trails
  • Enterprise$undefined/year
    • SKU-level price overrides for negotiated rates
    • Business unit reporting
    • SSO with SAML group mapping

Preact

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

Which should you pick?

Choose Infracost if

  • You need pull request cost diffs.
  • You want to start without paying.
  • You work on Web, macOS, Linux, Windows, Docker.
  • You also want multi-format parsing.
Infracost 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 Infracost or Preact better?
Neither clearly leads. Infracost 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, Infracost or Preact?
Infracost starts at Free and Preact at Free.
Does Infracost or Preact run on more platforms?
Infracost runs on Web, macOS, Linux, Windows, Docker. Preact runs on Web.
Can I use Infracost for free?
Both have a free tier, so you can try either at no cost before committing.
What is Infracost best used for?
Infracost is most often used for teams that want an expensive infrastructure change questioned at review rather than discovered on an invoice, platform groups enforcing tagging so cloud spend can be attributed to a team at all, organisations adopting finops practice without buying a full cloud management platform, engineers who want a cost figure in the editor while writing the terraform. Of those, teams that want an expensive infrastructure change questioned at review rather than discovered on an invoice and platform groups enforcing tagging so cloud spend can be attributed to a team at all are not what Preact is typically brought in for.
What can Infracost do that Preact cannot?
Infracost covers Pull request cost diffs, Multi-format parsing, Apache-2.0 CLI, FinOps policies. Preact covers 3kB runtime, preact/compat, Same modern API, Fast rendering.

Answered from the vendors’ own pages

Infracost: Is the open source version genuinely useful on its own?

Yes, for estimation. It parses your definitions and produces breakdowns and diffs locally. What it does not do is comment on pull requests, enforce policy or report across an organisation, all of which are hosted-only.

Preact: Is Preact free?

Yes, open source under the MIT licence.

Infracost: Will the estimate match my cloud bill?

No. It is list price. Committed use discounts, enterprise agreements and reserved instances need SKU-level overrides that sit in the Enterprise tier.

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.

Infracost: Why do my S3 and Lambda resources show no cost?

Usage-based resources need monthly usage values supplied in a usage file or defined centrally. Without them they estimate at zero, which is the documented behaviour and the most common way the tool misleads.

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.

Infracost: Has the licence ever changed?

No. The command line tool has been Apache 2.0 throughout, with no Business Source or AGPL episode, which is unusual in this category.

Infracost: What is a run?

Not defined on the public pricing page, and the run allowance is what separates the free and Starter tiers, so establish the definition before choosing between them.

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