Softwr

Cloud · head to head

Fly.io vs HTMX

Fly.io logo

Fly.io

Cloud

Deploy web applications globally

From
$29/month
Rated
-
Full reviewWebsite
HTMX logo

HTMX

Web Development

Lightweight JavaScript library enabling AJAX, WebSockets, and server-sent events in HTML

From
Free
Rated
-
Full reviewWebsite

The short version

  • Only HTMX 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; HTMX best suited for server-rendered architectures, not pure client-side SPAs
  • They diverge on capability: Fly.io covers Global deployment, HTMX covers AJAX requests.

Where they differ

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

Attributes where Fly.io and HTMX differ
AttributeFly.ioHTMX
Starting price$29/monthFree
Pricing modelusage-basedopen-source
Free tierNoYes
PlatformsWeb, Api, DockerWeb
CategoryCloudWeb Development
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 HTMX

  • AJAX requests
  • HTTP verb support
  • DOM targeting
  • Swap strategies
  • WebSocket support
  • Server-sent events
  • Out-of-band updates

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

HTMX

  • Building interactive applications without JavaScript framework complexitynot Fly.io
  • Server-rendered applications requiring dynamic updatesnot Fly.io
  • Adding interactivity to existing server-side applicationsnot Fly.io
  • Hypermedia-driven applications using HTML-first approachesnot 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

HTMX

  • Best suited for server-rendered architectures, not pure client-side SPAs
  • Limited client-side state management capabilities compared to frameworks
  • Smaller ecosystem with fewer third-party libraries and tools
  • Learning curve for developers from JavaScript framework backgrounds

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

HTMX

Free

No published plan breakdown. See the HTMX 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 HTMX if

  • You need ajax requests.
  • You want to start without paying.
  • You also want http verb support.
HTMX review

Questions people ask

Is Fly.io or HTMX better?
Neither clearly leads. Fly.io starts at $29/month and HTMX at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Fly.io or HTMX?
HTMX has a free tier; the other does not. Paid plans start at $29/month for Fly.io and Free for HTMX.
Does Fly.io or HTMX run on more platforms?
Fly.io runs on Web, Api, Docker. HTMX runs on Web.
Can I use HTMX for free?
Yes. HTMX 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 HTMX is typically brought in for.
What can Fly.io do that HTMX cannot?
Fly.io covers Global deployment, Docker support, Postgres databases, Redis support. HTMX covers AJAX requests, HTTP verb support, DOM targeting, Swap strategies.

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
HTMX: How big is the HTMX JavaScript library?

HTMX is only 16 kilobytes minified and gzipped with zero external dependencies.

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
HTMX: Can HTMX work with JSON APIs?

While HTMX is optimized for HTML responses, it can work with JSON through additional configuration and response handling.

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
HTMX: Does HTMX support real-time features like WebSockets?

Yes, HTMX includes support for WebSockets and server-sent events for real-time bidirectional communication.

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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