What are the best free alternatives to Fly.io?

Coolify, CapRover, Wrangler, Railway. All are reviewed on Stack Gems in the same category (self-hosted PaaS and deploy tools); 3 free or open source, 1 hosted with a real free tier.

Is there an open-source alternative to Fly.io?

Yes: Coolify (Apache-2.0), CapRover (Apache-2.0), Wrangler (Freemium).

Alternatives · Deploy & PaaS

Fly.io alternatives (2026)

Fly.io: Full VMs globally for developers who need more than serverless.

Its Catch: More operational than PaaS alternatives.

Below: 4 free or free-tier tools from the same category (self-hosted PaaS and deploy tools), free and open source first, then the closest match by shared tags. Each keeps its own Catch.

1.CoolifySelf-hosted Heroku alternative
Free / OSS · Apache-2.0 · 63.2k GitHub stars
VerdictSelf-hosted PaaS that is actually usable.
CatchSelf-hosting means self-operating. Some features are less polished than commercial alternatives. Single-server focus limits scale.
2.CapRoverFree PaaS you can run anywhere
Free / OSS · Apache-2.0 · 15.2k GitHub stars
VerdictSimple self-hosted PaaS for small deployments.
CatchLicense: Apache-2.0 with an appendix that overrides it — no redistributing paid versions of CapRover, its paid features cannot be modified, and changes to the free features must stay free and open source. Read it before building on top. Documentation assumes Docker knowledge. Some advanced features require manual configuration. Less active development than alternatives.
3.WranglerMIT/Apache CLI for Cloudflare Workers; Free plan is real
Free / OSS · Freemium · 4.6k GitHub stars
VerdictWorkers CLI with a real Free plan. Free to develop; pay Cloudflare when traffic or CPU leaves the free envelope.
CatchTied to Cloudflare’s platform: Free → Standard paid usage when you exceed quotas. Not a generic Node host and not Docker-on-VPS. Local emulation is good, production semantics still Cloudflare’s. Account + API token required to ship.
4.RailwayDeploy from GitHub with zero configuration
Free tier · Freemium
VerdictThe simplest path from code to production.
CatchLess control than VMs or containers. Pricing scales with usage. Customization options are limited. Some workloads do not fit the model.

FAQ

What are the best free alternatives to Fly.io?: Coolify, CapRover, Wrangler, Railway. All are reviewed on Stack Gems in the same category (self-hosted PaaS and deploy tools); 3 free or open source, 1 hosted with a real free tier.
What is the catch with Fly.io?: More operational than PaaS alternatives.
Is there an open-source alternative to Fly.io?: Yes: Coolify (Apache-2.0), CapRover (Apache-2.0), Wrangler (Freemium).