aws_amplify_app cost estimation

An aws_amplify_app is AWS's managed hosting and CI/CD for full-stack and static web apps — it builds from your repo and serves the result over a CDN. Cost is usage across three meters: build compute (~$0.01 per build-minute), data served out (~$0.15/GB), and stored artifacts (~$0.023/GB-month). A small app — 500 build minutes, 15 GB served, 5 GB stored — is ~$5 + $2.25 + $0.12 ≈ $7.37/month.

It's an inexpensive service for small-to-medium sites, with a generous free tier for new accounts. Cost scales with three independent factors: how often and how long your builds run (build minutes), how much traffic you serve (data out), and how much you store. For most apps the data-served charge grows fastest with popularity.

The levers: cache dependencies and prune build steps to shorten builds, and rely on Amplify's built-in CDN caching so served bytes are minimized. For very high traffic, compare against a CloudFront + S3 setup, which can be cheaper at scale than Amplify's bundled per-GB rate.

c3x prices the app from build minutes, data served, and storage as usage, so projected cost can be modelled.

Terraform example

A minimal but realistic configuration that C3X can estimate.

resource "aws_amplify_app" "web" {
  name       = "marketing-site"
  repository = "https://github.com/org/site"

  build_spec = <<-EOT
    version: 1
    frontend:
      phases:
        build:
          commands:
            - npm ci
            - npm run build
      artifacts:
        baseDirectory: dist
        files:
          - '**/*'
  EOT
}

Pricing dimensions

What you actually pay for when you provision aws_amplify_app.

Dimension	Unit	What's being charged
Build minutes	per minute	Build/CI compute time. Driven by build frequency and duration. $0.01/build-minute → 500 minutes = $5/month
Data served	per GB	Content served out over the CDN. Grows with traffic; usually the fastest-growing meter. $0.15/GB → 15 GB = $2.25/month
Storage	per GB-month	Stored build artifacts and hosted content. $0.023/GB-month → 5 GB ≈ $0.12/month

Sample C3X output

A small app: 500 build minutes + 15 GB served + 5 GB stored in a month:

aws_amplify_app.web
├─ Build minutes   500 minutes   $5.00
├─ Data served     15 GB         $2.25
└─ Storage         5 GB-month    $0.12
                   Monthly       $7.37

Optimization tips

Common ways to reduce aws_amplify_app cost without changing the workload.

Shorten and cache builds

Proportional to build time saved

Build minutes bill per minute. Cache dependencies between builds, prune unnecessary build steps, and avoid rebuilding on trivial changes — each shaves billable build time.

Lean on CDN caching for served data

Proportional to cache hit rate

Data served is usually the fastest-growing meter as an app gains traffic. Amplify's built-in CDN caching means cached content isn't re-served from origin — set sensible cache headers on static assets.

Compare CloudFront + S3 at high traffic

Workload-dependent at scale

For very high-traffic static sites, a CloudFront + S3 setup can be cheaper per GB than Amplify's bundled hosting rate. Amplify's value is the integrated build/deploy; at scale, evaluate the raw CDN path.

FAQ

How is AWS Amplify Hosting billed?

By usage across three meters: build minutes (~$0.01/min), data served out (~$0.15/GB), and stored artifacts (~$0.023/GB-month), with a generous free tier for new accounts. A small app is ~$7/month; data served grows fastest with traffic.

What drives Amplify cost as my app grows?

Data served. Build minutes and storage stay modest, but the per-GB served charge scales with traffic. Good CDN caching keeps it down, and at very high traffic a CloudFront + S3 setup may be cheaper.

How does c3x estimate the cost?

Amplify is usage-driven, so c3x models it from build minutes, data served, and storage in c3x-usage.yml. There's no standing fee to price.

Related resources

AWS

aws_cloudfront_distribution

Raw CDN path that can be cheaper than Amplify at high traffic

`aws_amplify_app` cost estimation