Small API
2 vCPU, 4GB RAM, 24/7
Fly.io 72% lower
As AI technology advances, choosing the right platform is crucial for your team's speed, governance, and long-term success. Both Fly.io and Azure have their strengths. The sections below compare them across developer experience, scalability, and total cost of ownership.
As AI technologies evolve, delivering and scaling applications has become essential for powering modern businesses, from AI startups to large-scale enterprises. There are various solutions available, including comprehensive cloud operating systems, managed Platform-as-a-Service (PaaS), and traditional IaaS. Selecting the right platform is crucial for your team's velocity, governance, and long-term success.
Fly.io and Azure both bring unique strengths to application delivery, each with its own capabilities and limitations. The best choice depends on your specific use case and requirements. In the following sections, we'll compare both platforms regarding developer experience, scalability, and total cost of ownership, helping you determine the most suitable option for your needs—even if it's not us.
| Infrastructure | Edge micro-VMs (Firecracker) | Azure-managed PaaS |
| Source Available | ||
| Deployment Options | Cloud only | Azure cloud only |
| Free Trial | Free allowance (shared CPU, limited) | Azure free tier (limited) |
| Max vCPU per Service | Plan-based (per VM size) | Plan-based (App Service Plan) |
| Max RAM per Service | Plan-based (per VM size) | Plan-based (App Service Plan) |
| Custom Domains | ||
| Replicas per Service | (within org limits) | Plan-based (scale out) |
| Cron Jobs | Scheduled machines | WebJobs/Functions |
| Log Retention | Limited (plan-based) | Configurable (Azure Monitor) |
| Scale-to-Zero | (saves on idle) | |
| App Marketplace |
Cost evidence
Estimates use the listed average CPU and RAM for a 30-day month. Storage and egress are excluded unless a platform note says otherwise.
Small API
2 vCPU, 4GB RAM, 24/7
Medium App
8 vCPU, 16GB RAM, 24/7
Production Stack
16 vCPU, 32GB RAM, 24/7
2 vCPU, 4GB RAM, 24/7
Fly.io 72% lower
8 vCPU, 16GB RAM, 24/7
Fly.io 60% lower
16 vCPU, 32GB RAM, 24/7
Fly.io 15% lower
Fly.io calculation: estimated using always-on VM pricing (CPU + RAM) across 720 hours/month
Azure calculation: App Service Plan tiers + monitoring over 720 hours/month
Fly.io is an edge application platform that runs apps as lightweight Firecracker micro-VMs across a global network. It emphasizes Dockerfile-first deployments and a powerful CLI (`flyctl`) for fast, scriptable workflows. Fly.io provides Anycast networking, global routing, per-region scaling, and scale-to-zero for idle workloads, making it a strong fit for latency-sensitive apps and globally distributed teams.
Azure App Service is Microsoft managed PaaS for hosting web apps, APIs, and containerized services. It integrates with Azure DevOps/GitHub, supports deployment slots, and scales within App Service Plans. It a strong fit for teams already on Azure who want a managed runtime with deep Azure integrations and enterprise compliance support.
Need global low-latency delivery with edge deployments
Prefer a CLI-first workflow with Dockerfile control
Want Anycast routing and multi-region replicas
Have spiky traffic that benefits from scale-to-zero
Run apps close to users for latency-sensitive experiences
Are comfortable with usage-based billing
Building .NET applications with Microsoft tooling
Need Azure service integration (Cosmos DB, Blob Storage, etc.)
Require enterprise compliance with Azure certifications
Want deployment slots for zero-downtime staging
Using Azure AD for identity and access management
Need global Azure regions for worldwide deployment
Everything you need to know about Fly.io and Azure.