Small API
2 vCPU, 4GB RAM, 24/7
Sealos 71% lower
As AI technology advances, choosing the right platform is crucial for your team's speed, governance, and long-term success. Both Sealos and Fly.io 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.
Sealos and Fly.io 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 | Standard Kubernetes | Edge micro-VMs (Firecracker) |
| Source Available | 100% source-available (Apache 2.0) | |
| Deployment Options | Cloud Self-hosted Hybrid | Cloud only |
| Free Trial | 7 days, 4 vCPU + 4GB (no credit card) | Free allowance (shared CPU, limited) |
| Max vCPU per Service | Plan-based (4-64 vCPU) | Plan-based (per VM size) |
| Max RAM per Service | Plan-based (4-128 GB) | Plan-based (per VM size) |
| Custom Domains | Unlimited | |
| Replicas per Service | Unlimited (within quota) | (within org limits) |
| Cron Jobs | Unlimited | Scheduled machines |
| Log Retention | Configurable | Limited (plan-based) |
| 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
Sealos 71% lower
8 vCPU, 16GB RAM, 24/7
Sealos 57% lower
16 vCPU, 32GB RAM, 24/7
Sealos 15% lower
Plan prices include the resource package listed on the Sealos pricing page.
Fly.io calculation: estimated using always-on VM pricing (CPU + RAM) across 720 hours/month
Sources:Sealos Pricing·Fly.io Pricing
Sealos is an AI-native Cloud Operating System built on Kubernetes that unifies the entire application lifecycle, from development in Cloud Development Environments (CDEs) to production deployment and management. It is perfect for building and scaling modern AI applications, SaaS platforms, managed databases (MySQL, PostgreSQL, Redis, MongoDB) and complex microservice architectures. The platform is 100% source-available, and for production you can choose either a fully managed cloud service or self-host on your own infrastructure.
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.
Predictable costs for 24/7 production workloads
Cloud Development Environment (CDE) for consistent dev/prod environments
Self-hosting option for data sovereignty or compliance (100% source-available)
Kubernetes-native control with full API access
100+ ready-to-deploy apps from the marketplace
Enterprise multi-tenancy with granular RBAC and resource quotas
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
Everything you need to know about Sealos and Fly.io.