cloudfront-functions.html

AWS CloudFront Functions

Sub-millisecond JS at CloudFront edge. Lighter than Lambda@Edge, narrower scope.

VISIT AWS CLOUDFRONT FUNCTIONS

Quick facts

  • CategoryCDN-attached function
  • LanguageJS (subset)
  • PricingPaid
  • LicenseProprietary
  • Created2021
  • GitHub starsclosed
  • Cold startinstant
  • PoPs~600
  • Node-compatNo

What it is

CloudFront Functions runs lightweight JavaScript at CloudFront PoPs in sub-millisecond time. Restricted runtime — no full V8, smaller API surface than Workers. Used for header manipulation, URL rewriting, simple auth checks. Cheaper than Lambda@Edge, narrower scope.

Best for

  • AWS-locked teams needing fast header / URL manipulation at edge
  • Cost-sensitive AWS edge workloads (cheaper than Lambda@Edge)
  • Simple viewer-request transformations

When not to pick it

Skip CloudFront Functions for anything beyond simple transformations — the runtime is restricted. For serious edge logic, Lambda@Edge or Cloudflare Workers.

My take

Niche but useful inside AWS. Outside that ecosystem, Cloudflare Workers covers the same use cases with a richer runtime.

Links

Compare AWS CloudFront Functions side-by-side

AWS CloudFront Functions vs AWS Lambda@Edge →

Similar tools you should also consider

AWS Lambda@Edge

AWS Lambda functions running on CloudFront. Full Node, slow cold starts, AWS-locked.

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Cloudflare Workers

V8 isolates on 300+ PoPs. Sub-millisecond cold starts, lowest cost at scale, the edge default.

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If AWS CloudFront Functions is your pick — the next conversation is short

The 30-min call is where your edge runtime choice becomes a real architecture, an integration plan with your data layer + auth + build pipeline, and a price range you can take to your stakeholders.