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Cloud · head to head

Fly.io vs Rook

Fly.io logo

Fly.io

Cloud

Deploy web applications globally

From
$29/month
Rated
-
Full reviewWebsite
Rook logo

Rook

Cloud

Kubernetes operator that deploys and manages Ceph storage clusters

From
Free
Rated
-
Full reviewWebsite

The short version

  • Only Rook has a free tier, so it costs nothing to try first.
  • Each has a real cost: Fly.io egress is priced by destination region, from $0.02 per GB in North America and Europe to $0.12 per GB for Africa and India, so the same traffic costs six times more depending on where users are; Rook rook automates Ceph but does not abstract it, so an incident still demands Ceph expertise, and organisations without it end up hiring consultants at exactly the wrong moment.
  • They diverge on capability: Fly.io covers Global deployment, Rook covers Ceph operator.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Fly.io and Rook actually diverge.

Attributes where Fly.io and Rook differ
AttributeFly.ioRook
Starting price$29/monthFree
Pricing modelusage-basedOpen source, no licence fee
Free tierNoYes
PlatformsWeb, Api, DockerLinux, Kubernetes
Founded2020Unknown

Identical on both: user rating (Not yet rated), category (Cloud).

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 Fly.io

  • Global deployment
  • Docker support
  • Postgres databases
  • Redis support
  • Auto-scaling
  • Health checks
  • Backups
  • Monitoring

Only in Rook

  • Ceph operator
  • Block, file and object
  • Erasure coding
  • CSI driver
  • Automated upgrades
  • Multi-cluster mirroring

What people use each for

The jobs each tool is most often brought in to do.

Fly.io

  • Deploying containerised applications close to users across regionsnot Rook
  • Running full stack apps and databases on managed machinesnot Rook

Rook

  • An on-premises Kubernetes platform needing block, shared filesystem and S3 storage without buying three productsnot Fly.io
  • A team that already runs Ceph and wants its lifecycle managed declaratively inside Kubernetesnot Fly.io
  • A large cluster where three-way replication overhead is unaffordable and erasure coding is requirednot Fly.io
  • An organisation building a private cloud that cannot use managed cloud storage services for residency reasonsnot Fly.io

Where each one falls short

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

Fly.io

  • Egress is priced by destination region, from $0.02 per GB in North America and Europe to $0.12 per GB for Africa and India, so the same traffic costs six times more depending on where users are
  • Stopped machines still bill at $0.15 per GB of root filesystem a month, so a paused service is not a free one
  • Volumes are billed on provisioned capacity rather than usage, at $0.15 per GB a month
  • Reservation discounts of 40% require paying a year up front, from $36 to $1,440
  • Fly Kubernetes is a separate $75 a month per cluster
  • Dedicated IPv4 addresses are $2 a month each

Rook

  • Rook automates Ceph but does not abstract it, so an incident still demands Ceph expertise, and organisations without it end up hiring consultants at exactly the wrong moment.
  • There is no vendor and no SLA; the realistic commercial support routes are IBM Red Hat OpenShift Data Foundation or an independent Ceph consultancy, both of which change the cost picture entirely.
  • Ceph is resource hungry, needing substantial memory and dedicated disks per OSD, so the hardware cost of a properly sized cluster is often underestimated.
  • Recovery and rebalancing after a disk or node failure generates heavy background input and output that can degrade application performance for hours, which surprises teams sizing for steady state.
  • Minimum viable clusters require several nodes with several disks each, so it is impractical at small scale and the entry hardware cost exceeds simpler alternatives.

Pricing, plan by plan

Fly.io

$29/month
  • Pay-as-You-Go$null/mo
    • Micro VMs and persistent storage charged by usage
    • FlyCTL CLI
    • Unlimited users and organizations
  • Serious Support$29/month
    • Access to dedicated engineering team
    • All Pay-as-You-Go features
  • Machine Reservation Blocks$null/mo
    • 40% discount on machine usage
    • Requires upfront payment for savings
  • Compliance Package$99/month
    • HIPAA compliance
    • BAAs
    • SOC2 documentation

Rook

Free
  • RookFree
    • Apache 2.0 licensed, no licence fee
    • Graduated CNCF project
    • Community support via GitHub and Slack only

Which should you pick?

Choose Fly.io if

  • You need global deployment.
  • You work on Web, Api, Docker.
  • You also want docker support.
Fly.io review

Choose Rook if

  • You need ceph operator.
  • You want to start without paying.
  • You work on Linux, Kubernetes.
  • You also want block, file and object.
Rook review

Questions people ask

Is Fly.io or Rook better?
Neither clearly leads. Fly.io starts at $29/month and Rook at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Fly.io or Rook?
Rook has a free tier; the other does not. Paid plans start at $29/month for Fly.io and Free for Rook.
Does Fly.io or Rook run on more platforms?
Fly.io runs on Web, Api, Docker. Rook runs on Linux, Kubernetes.
Can I use Rook for free?
Yes. Rook has a free tier, so you can try it without paying. Fly.io starts at $29/month.
What is Fly.io best used for?
Fly.io is most often used for deploying containerised applications close to users across regions, running full stack apps and databases on managed machines. Of those, deploying containerised applications close to users across regions and running full stack apps and databases on managed machines are not what Rook is typically brought in for.
What can Fly.io do that Rook cannot?
Fly.io covers Global deployment, Docker support, Postgres databases, Redis support. Rook covers Ceph operator, Block, file and object, Erasure coding, CSI driver.

Answered from the vendors’ own pages

Fly.io: Is there a free tier for Fly.io?

Fly.io does not advertise a free tier. The base plan is pay-as-you-go with usage-based pricing for Micro VMs and persistent storage. All users get FlyCTL CLI, unlimited organizations, private networking, SSO, ACLs, and scoped tokens.

Source
Rook: Who supports it in production?

Nobody by default. IBM sells Red Hat OpenShift Data Foundation, which is supported Rook and Ceph, and independent consultancies sell Ceph support. Decide this before deployment.

Fly.io: How much does Fly.io Serious Support cost?

Serious Support costs 29 USD per month and provides access to a dedicated engineering team while maintaining all pay-as-you-go features for Micro VMs and storage.

Source
Rook: Does it need Ceph knowledge?

Yes. Rook handles deployment and routine operations, but troubleshooting a degraded cluster is a Ceph skill and there is no way around it.

Fly.io: What does Fly.io Compliance Package include?

The Compliance Package is 99 USD per month and includes HIPAA compliance, BAAs, and SOC2 documentation for organizations requiring compliance certifications.

Source
Rook: Can it replace an object storage appliance?

Functionally yes, through the RADOS gateway, but you take on the operations that an appliance vendor would otherwise carry.

Fly.io: Does Fly.io offer discounts for upfront commitment?

Yes, Fly.io offers Machine Reservation Blocks with 40% discount on machine usage. This requires upfront payment but applies savings on infrastructure costs.

Source
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