App platforms

Fly.io vs Heroku

Choose Fly.io when the app should run close to users in more than one region and you can watch a usage bill. Choose Heroku when you want buildpacks and a catalog of add-ons and you already expect to pay for dynos.

Fly.io

Run apps close to users on a global edge

Usage-based

Strengths

  • Machines can run in many regions
  • Fits latency-sensitive APIs

Limits

  • The bill is usage-based, so it is harder to cap
  • You still manage app config and regions

Vendor pricing Alternatives

Heroku

Mature app platform with a large add-on catalog

Paid dynos

Strengths

  • Add-ons cover databases, cache, and logging
  • Buildpacks still cover common stacks

Limits

  • Dynos cost more than a comparable VPS
  • There is no permanent free dyno

Vendor pricing Alternatives