Deploy a Docker App for Free

Render offers the clearest free path for a small HTTP container, while Railway and Fly.io provide trial or usage-based alternatives. The decisive issues are port binding, health checks and whether the app writes durable data to disk.

PocketBase · pocketbase/pocketbase

Use Render for a public demo container that can sleep and does not need a persistent disk.

Use Railway for a polished Docker workflow when trial or low-cost billing is acceptable.

Use Fly.io for Machines, regions and volumes when you accept usage-based pricing.

Move databases and uploads outside the container before relying on any free deployment.

Best free hosts

Render Render Services Inc.

Render is a unified cloud to build and run all your apps and websites with free TLS certificates, a global CDN, private networks and auto deploys from Git.

PaaS #backend#database#docker

Free tier

750 hours/month for web services

Paid from $7/mo · 4 regions

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Railway Railway Corp

Railway is an infrastructure platform where you can provision infrastructure, develop with it locally, and then deploy to the cloud.

PaaS #backend#database#deployment

Free tier

30-day trial with $5 usage credit, then $1/month minimum

Paid from $1/mo · 4 regions

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Fly.io Fly.io Inc.

Fly.io transforms containers into micro-VMs that run on their hardware in cities close to your users.

Container Hosting #containers#edge#docker

No free tier

Visit Fly.io

Render is the primary recommendation for this deployment path.

Deployment path

1 Build the image locally and verify it starts with production environment variables.
2 Run as a non-root user, expose a health endpoint and listen on `0.0.0.0` using the platform port.
3 Add `.dockerignore`, pin the base image and keep credentials out of build arguments and layers.
4 Create a Render web service with Docker as the runtime, then configure secrets and the health-check path.
5 Deploy and test startup, idle wake-up, graceful shutdown and a full redeploy.
6 Confirm all data survives outside the ephemeral filesystem before inviting users.

Production-minded container setup

Keep the runtime image small, deterministic and disposable. A restart should recreate the service from the image and external state without manual repair. Emit logs to standard output, handle termination signals and fail the health check when critical dependencies are unavailable.

Free container hosting is ideal for demonstrations. Move to paid resources before uptime, storage, backups or predictable latency become product requirements.

FAQ

Can I deploy any Docker image for free?

Only if it satisfies the host's architecture, port and runtime requirements. Databases and stateful infrastructure are usually poor fits for an ephemeral free web service.

Why does my container fail to receive traffic?

The process often listens only on localhost or a hard-coded port. Bind to `0.0.0.0` and the port supplied by the platform.

Where should uploaded files go?

Use durable object storage or a paid persistent volume. A free Render web-service filesystem is ephemeral.