Softwr

Cloud · head to head

Fly.io vs SST

Fly.io logo

Fly.io

Cloud

Deploy web applications globally

From
$29/month
Rated
-
Full reviewWebsite
SST logo

SST

Cloud

Build full-stack apps on your own infrastructure

From
Free
Rated
-
Full reviewWebsite

The short version

  • Only SST 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; SST primarily optimized for AWS with Cloudflare support
  • They diverge on capability: Fly.io covers Global deployment, SST covers Single config file.

Where they differ

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

Attributes where Fly.io and SST differ
AttributeFly.ioSST
Starting price$29/monthFree
Pricing modelusage-basedUnknown
Free tierNoYes
PlatformsWeb, Api, DockerAWS, Cloudflare, Node.js
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 SST

  • Single config file
  • Resource linking
  • Local development
  • Multi-cloud support
  • Multiple deployment stages
  • VPC tunneling

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 SST
  • Running full stack apps and databases on managed machinesnot SST

SST

  • Deploying Next.js frontends with serverless backendsnot Fly.io
  • Managing databases and storage alongside application codenot Fly.io
  • Creating staging environments for feature testingnot 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

SST

  • Primarily optimized for AWS with Cloudflare support
  • Learning curve for developers unfamiliar with infrastructure concepts
  • Limited documentation for some advanced use cases

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

SST

Free

No published plan breakdown. See the SST review.

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 SST if

  • You need single config file.
  • You want to start without paying.
  • You work on AWS, Cloudflare, Node.js.
  • You also want resource linking.
SST review

Questions people ask

Is Fly.io or SST better?
Neither clearly leads. Fly.io starts at $29/month and SST at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Fly.io or SST?
SST has a free tier; the other does not. Paid plans start at $29/month for Fly.io and Free for SST.
Does Fly.io or SST run on more platforms?
Fly.io runs on Web, Api, Docker. SST runs on AWS, Cloudflare, Node.js.
Can I use SST for free?
Yes. SST 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 SST is typically brought in for.
What can Fly.io do that SST cannot?
Fly.io covers Global deployment, Docker support, Postgres databases, Redis support. SST covers Single config file, Resource linking, Local development, Multi-cloud support.

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
SST: Is SST free?

Yes, SST is open source and free. You only pay for cloud resources from AWS and other providers.

Source
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
SST: What cloud providers does SST support?

SST supports over 150 providers through built-in AWS and Cloudflare components, plus Pulumi and Terraform providers.

Source
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
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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