Softwr

Cloud · head to head

Fly.io vs PartyKit

Fly.io logo

Fly.io

Cloud

Deploy web applications globally

From
$29/month
Rated
-
Full reviewWebsite
P

PartyKit

Developer Tools

Platform for building and deploying realtime multiplayer servers on the edge

From
Free
Rated
-
Full reviewWebsite

The short version

  • Only PartyKit 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; PartyKit documentation and FAQ material on the marketing site is sparse compared to larger realtime platforms.
  • They diverge on capability: Fly.io covers Global deployment, PartyKit covers Stateful edge servers.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

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

Attributes where Fly.io and PartyKit differ
AttributeFly.ioPartyKit
Starting price$29/monthFree
Pricing modelusage-basedfreemium
Free tierNoYes
PlatformsWeb, Api, Dockerweb, api
CategoryCloudDeveloper Tools
Founded2020Unknown

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

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 PartyKit

  • Stateful edge servers
  • WebSocket-first API
  • CRDT library compatibility
  • Framework integrations
  • Global edge deployment
  • Custom domains

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

PartyKit

  • Multiplayer collaborative appsnot Fly.io
  • Realtime AI agent backendsnot Fly.io
  • Live cursors and presencenot Fly.io
  • Collaborative whiteboards and documentsnot 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

PartyKit

  • Documentation and FAQ material on the marketing site is sparse compared to larger realtime platforms.
  • Commercial free tier requires deploying to the user's own Cloudflare account, adding setup complexity.
  • Storage on the free Individual plan clears every 24 hours, limiting it to prototyping rather than persistent production data.
  • Smaller ecosystem and community than more established realtime infrastructure providers.

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

PartyKit

Free
  • IndividualFree
    • Up to 10 live projects
    • Deploy to the global edge platform
    • Storage clears every 24 hours
  • CommercialFree
    • Unlimited projects
    • Custom domains
    • Runs on your own Cloudflare account; pay only Cloudflare usage

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 PartyKit if

  • You need stateful edge servers.
  • You want to start without paying.
  • You work on web, api.
  • You also want websocket-first api.
PartyKit review

Questions people ask

Is Fly.io or PartyKit better?
Neither clearly leads. Fly.io starts at $29/month and PartyKit at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Fly.io or PartyKit?
PartyKit has a free tier; the other does not. Paid plans start at $29/month for Fly.io and Free for PartyKit.
Does Fly.io or PartyKit run on more platforms?
Fly.io runs on Web, Api, Docker. PartyKit runs on web, api.
Can I use PartyKit for free?
Yes. PartyKit 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 PartyKit is typically brought in for.
What can Fly.io do that PartyKit cannot?
Fly.io covers Global deployment, Docker support, Postgres databases, Redis support. PartyKit covers Stateful edge servers, WebSocket-first API, CRDT library compatibility, Framework integrations.

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
PartyKit: How much does PartyKit cost?

PartyKit is completely free. Both the Individual and Commercial plans have no upfront costs.

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
PartyKit: What is PartyKit's Individual plan?

The Individual plan is free and includes deployment to a global edge platform, support for up to 10 live projects, and is suitable for small projects. Storage is cleared every 24 hours.

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
PartyKit: What is PartyKit's Commercial plan?

The Commercial plan is free but requires deploying to your own Cloudflare account. It includes custom domains, unlimited projects, and you pay only your Cloudflare usage costs.

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
PartyKit: Can I upgrade from Individual to Commercial plan?

Yes, both plans are free but offer different feature sets. The Commercial plan removes project restrictions but requires managing your own Cloudflare infrastructure.

Source
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