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Developer Tools · head to head

Deno vs Preact

Deno logo

Deno

Developer Tools

A fast, open-source, fully Node-compatible JS runtime with TypeScript baked right in

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: Deno egress bandwidth overage costs $0.20/GB which can become expensive for high-traffic applications; Preact compatibility through preact/compat is good but not total, and some React libraries break in ways that are hard to diagnose
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which Deno and Preact actually diverge.

Attributes where Deno and Preact differ
AttributeDenoPreact
Pricing modelfreemiumOpen source, no licence fee
CategoryDeveloper ToolsWeb Development

Identical on both: starting price (Free), free tier (Yes), platforms (Web), 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 Deno

Nothing recorded that Preact does not also cover.

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.

Deno

  • Running TypeScript natively without transpilation overheadnot Preact
  • Migrating Node.js applications to secure-by-default runtimenot Preact
  • Deploying edge functions and serverless containers seamlesslynot Preact
  • Consolidating developer tools into single binarynot Preact

Preact

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

Where each one falls short

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

Deno

  • Egress bandwidth overage costs $0.20/GB which can become expensive for high-traffic applications
  • CPU time overage is $0.10/hour on Pro and Builder tiers, adding to costs for compute-intensive workloads
  • Enterprise pricing is not disclosed; requires sales contact

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

Deno

Free
  • FreeFree
    • 1 million requests/month
    • 20GB egress bandwidth
    • 10 apps
  • Pro$20/month
    • 5 million requests/month
    • 200GB egress
    • 50 apps
  • Builder$200/month
    • 25 million requests/month
    • 2,000GB egress
    • 10,000 apps
  • Enterprise$null/month
    • Custom limits on all metrics
    • 99.95% reliability SLA
    • Email support with SLA

Preact

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

Which should you pick?

Choose Deno if

  • You want to start without paying.
Deno 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 Deno or Preact better?
Neither clearly leads. Deno 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, Deno or Preact?
Deno starts at Free and Preact at Free.
Does Deno or Preact run on more platforms?
Both run on Web, so platform support will not decide this one for you.
Can I use Deno for free?
Both have a free tier, so you can try either at no cost before committing.
What is Deno best used for?
Deno is most often used for running typescript natively without transpilation overhead, migrating node.js applications to secure-by-default runtime, deploying edge functions and serverless containers seamlessly, consolidating developer tools into single binary. Of those, running typescript natively without transpilation overhead and migrating node.js applications to secure-by-default runtime are not what Preact is typically brought in for.
What can Deno do that Preact cannot?
Preact covers 3kB runtime, preact/compat, Same modern API, Fast rendering.

Answered from the vendors’ own pages

Deno: How much does Deno Deploy cost?

Deno Deploy offers a free tier at $0/month, Pro at $20/month, and Builder at $200/month. Enterprise has custom pricing. All plans include base request and bandwidth limits, with overage charges for additional usage.

Source
Preact: Is Preact free?

Yes, open source under the MIT licence.

Deno: What are Deno Deploy's overage charges?

Egress bandwidth overages cost $0.20 per GB. CPU time overages are $0.10 per hour on Pro and Builder tiers. Memory time and KV database operations also incur charges beyond included limits.

Source
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.

Deno: How many apps can I deploy on Deno's free plan?

The free tier includes 10 apps with up to 1 concurrent build. Pro tier supports 50 apps with 3 concurrent builds, and Builder supports 10,000 apps with 20 concurrent builds.

Source
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.

Deno: How many team members can access Deno Deploy?

The free tier supports up to 3 team members. Pro supports 10 team members. Builder supports 25 team members. Enterprise has custom seat limits.

Source
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