Astro on Fly.io
Fly.io publishes its own guide for deploying Astro.
Content-focused framework that ships zero JavaScript by default and renders components from several UI libraries.
What Astro needs.
Every host claims to run Astro, so the claim on its own decides nothing. These are the things Astro actually requires from the platform underneath it, and what Fly.io publishes about each. Fly.io documents 2 of the 4.
Build allowance
Not documented
Astro prerenders by default, so most of the work happens at build time and the build allowance is the real constraint.
Concurrent builds
Not documented
A content site rebuilds on every edit. One build slot turns a busy publishing day into a queue.
Edge network
Limited
A prerendered Astro site is a directory of static files. After that, the only thing left that affects speed is where they are served from.
Sources (1) →Sources ↓
- The Fly.io Architecture — Fly Docs ↗
“We broadcast and accept traffic from ranges of IP addresses (both IPv4 and IPv6) in all our datacenters. When we receive a connection on one of those IPs, we match it back to an active customer application, and then proxy the TCP connection to the closest available microVM.”
Read 2026-09-05 · official docs
Git deployment
Limited
Astro's usual workflow is a push that triggers a build. Anything else means wiring the build yourself.
Sources (1) →Sources ↓
- Continuous deployment with GitHub Actions — Fly Docs ↗
“push to the repository's master branch. If your repository uses a default branch other than master, such as main, then you should change that here. [...] jobs: deploy: name: Deploy app runs-on: ubuntu”
Read 2026-09-07 · official docs
What Fly.io documents.
Fly.io publishes its own guide for deploying Astro.
You can deploy your Astro app on Fly.io with minimal effort, our CLI will do the heavy lifting.
Sources (1) →Sources ↓
- Run an Astro App · Fly Docs ↗
“You can deploy your Astro app on Fly.io with minimal effort, our CLI will do the heavy lifting.”
Read 2026-09-05 · official docs
Astro features on Fly.io
Capabilities Fly.io documents specifically for Astro, with the constraint it documents alongside each.
ssr_adapter
Supported
There are a handful of adapters that are officially maintained by the Astro team. When using the @astrojs/node adapter, Fly.io will automatically detect this during fly launch and if no existing Dockerfile is found, it will generate a new one with the appropriate start command and environment variables.
zero_config_deploy
Supported
Scanning source code Detected an Astro app [...] running fly launch will generate a Dockerfile for you if one does not already exist
Sources (1) →Sources ↓
- Run an Astro App · Fly Docs ↗
“There are a handful of adapters that are officially maintained by the Astro team. When using the @astrojs/node adapter, Fly.io will automatically detect this during fly launch and if no existing Dockerfile is found, it will generate a new one with the appropriate start command and environment variables.”
Read 2026-09-13 · official docs
What it costs to run there.
- Pricing model
- Usage-based, no compute plan tiers; billing is pro-rated for the time resources are provisioned.
- When you exceed a cap
- No plan cap to exceed — Fly bills per second for provisioned resources. The only documented enforcement is unspecified automated scaling limits, which surface as an error message (platform-wide, all plans)
- Regions
- 17 regions
Sources (2) →Sources ↓
- Pricing — Fly.io Docs ↗
“Plans get complicated, so we just charge based on usage. Pick and choose which pieces you need for your application; that's all you'll see on your invoice.”
Read 2026-09-14 · official docs
- Regions - Fly.io Documentation ↗
“You can host your apps in any of the following regions. Region ID Region Location Gateway MPG ams Amsterdam, Netherlands ✓ ✓ arn Stockholm, Sweden ✓ cdg Paris, France ✓ dfw Dallas, Texas (US) ✓ ✓ ewr Secaucus, NJ (US) ✓ fra Frankfurt, Germany ✓ ✓ gru Sao Paulo, Brazil ✓ iad Ashburn, Virginia (US) ✓ ✓ jnb Johannesburg, South Africa lax Los Angeles, California (US) ✓ ✓ lhr London, United Kingdom ✓ ✓ nrt Tokyo, Japan ✓ ✓ ord Chicago, Illinois (US) ✓ ✓ sin Singapore, Singapore ✓ ✓ sjc San Jose, California (US) ✓ ✓ syd Sydney, Australia ✓ ✓ yyz Toronto, Canada ✓ ✓”
Read 2026-09-27 · official docs
Whether it suits you.
Workloads that ship as Docker images and need placement in particular regions. Billing is purely usage-based with no plan tiers, which suits spiky or region-pinned traffic better than a flat monthly fee.
Consider something else if…
You want a predictable flat bill rather than charges that track the resources provisioned for each app.
Visit Fly.io documentation