vioscaleAI
Comparison

Fly.io vs Kamal

On the evidence we track, Fly.io leads this comparison with a composite score of 71/100. Scores are only directly comparable because these tools share a category; the full breakdown and every source is below.

Fly.io full profile →Kamal full profile →
Machine formatsMarkdownJSONGraphQLMarkdown is open. JSON and GraphQL need a free key.
★Fly.io71
Kamal50
Score
vioscaleAI score
Fly.io71 / 100medium · 63%
Kamal50 / 100low · 24%
Pricing
Free tier
Fly.io✓
Kamal–
Model
Price level
Fly.iounknown
Kamalfree
Transparent
Fly.io✗
Kamal–
Integrations
Count
Fly.io4
Kamal–
Security
Hipaa
Fly.io✓
Kamal–
Iso27001
Fly.io✓
Kamal–
Soc2
Fly.io✓
Kamal–
Trust center
Vulnerabilities
Reliability
Sla pct
Fly.io99.9
Kamal–
Status page
Fly.io✓
Kamal–
Adoption
Dependent repos
Fly.io–
Kamal3
Github stars
Fly.io–
Kamal14,634
Activity
Commits last 30d
Fly.io–
Kamal29
Release
Cadence days
Fly.io–
Kamal19
History
Fly.io–
Kamal20 items
License
Spdx
Fly.io–
KamalMIT
Language
Primary
Fly.io–
KamalRuby
Market
Availability
Content
Faq
Fly.io7 items
Kamal5 items

Features

The capabilities each product documents. These tools do not share a category taxonomy, so this aligns what each vendor states rather than a normalised feature set.

Declared feature comparison
FeatureFly.ioKamal
Autoscalinghorizontal-
Build systemdockerfile-
Cli and api✓-
Container deploy✓-
Custom domains tls✓-
Env secrets✓-
Hostingcloud-
Managed databases✓-
Regionsmulti-
Rollbacks✓-
RuntimesDocker containers, Node.js, Deno, and other containerized runtimes-

What each one is

The product in its own terms, so the numbers below have context.

Fly.io

Leader

A cloud service offering hardware-isolated Linux virtual machines optimized for running AI agents and tools, featuring persistent storage, checkpoint and rollback capabilities, and API gateway-based credential management.

Independently observed

Kamal

An open-source deployment tool that enables zero-downtime releases of containerized web applications, supporting deployment from physical servers to cloud VMs with multi-server orchestration via SSH.

Independently observed

Pricing

List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.

Fly.io

Leader
from $29/moUsage-based

Usage-based pricing (pay-as-you-go) with optional prepayment for 40% discount. Serious Support from $29/month. HIPAA compliance at $99/month. Enterprise available via contact.

  • Pay-as-You-GoPay only for what you use
    • Micro VMs
    • Persistent storage
    • Private networking
    • Unlimited users per organization
  • Serious SupportStarting at $29/month
    • Dedicated support team
  • HIPAA Compliance$99/month
    • HIPAA-compliant workloads
    • BAAs
    • SOC2 certification
  • Machine ReservationSave 40% with upfront commitment
    • 40% discount vs pay-as-you-go
  • EnterpriseContact sales
    • Custom resource configurations
    • SLA requirements
    • Emergency support
as of verify ↗

Kamal

Open source
as of verify ↗

Platform & deployment

Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.

Platforms
macOS
Fly.io✗
Kamal✓
Linux
Fly.io✗
Kamal✓
CLI
Fly.io✓
Kamal✓
Deployment
Cloud / SaaS
Fly.io✓
Kamal✓
On-premise
Fly.io✗
Kamal✓

Integrations

What each product connects to. Counts come from the vendor's own integration directory where one exists.

Fly.io

Leader
9 total
  • Sentry
  • Supabase
  • Upstash
  • LiteFS
  • Tigris
  • OpenRouter
  • GitHub
  • Slack
  • HTTP API
Independently observed

Kamal

Not documented yet.

Still deciding?

Fly.io or Kamal: which one depends on you

A composite score cannot know your constraints. Describe them and both get re-weighted against what you actually need, with the evidence behind every position.

Free to run, no account needed to start. How the evaluation works

Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.