How to deploy a Docker container for free

You can deploy a Docker container for free on blitz.cloud: create an account without a credit card, click Host something new, search Docker Hub for the image, pick a version and a name, and it runs under an HTTPS address like whoami.yourname.blitz.cloud. The free plan has no time limit. An app nobody visits for 15 minutes goes to sleep and wakes on the next visit. The catch is that the image has to be public on Docker Hub, built for amd64, and able to run without root.

What you need

• A blitz.cloud account. Sign up at dashboard.blitz.cloud with email, GitHub or Google, and confirm your email address. Until it is confirmed you can't create apps.
• A public image. The wizard searches Docker Hub as you type. For ghcr.io, Quay or another public registry, type the full name, such as ghcr.io/owner/image. Private images need a login blitz.cloud doesn't have.

Will my image run?

Most failed first attempts come down to two things. You can check both on your own machine in a minute. Root is not one of them: an image that starts as root runs as root inside its own sandbox here.

1. Architecture. blitz.cloud runs on amd64 servers. Images built on an Apple Silicon Mac with a plain docker build are arm64-only and will not start. Build with --platform linux/amd64.
2. A declared port. Listen on something like 8080 and declare it with EXPOSE 8080 in the Dockerfile, so blitz.cloud picks it up without you typing it.

This command runs an image roughly the way blitz.cloud does:

docker run --rm --platform linux/amd64 --security-opt no-new-privileges \
  -p 8080:8080 yourname/your-image:1.0.0

If curl http://localhost:8080 answers, you are in good shape.

Deploy the container

1. Sign in at dashboard.blitz.cloud. The first time, you claim your address, for example lena. Your apps will live under lena.blitz.cloud.
2. Click Host something new and choose "An app from Docker Hub".
3. Type the image name into Which app? and pick it from the list. Official images are marked. A repository you pushed a few minutes ago can take a while to appear in Docker Hub's search.
4. Choose a Version. Tags like latest are marked "follows new releases"; a fixed tag like 1.0.0 never changes. Click Continue.
5. The next screen shows What this app needs: the port it will be reached on, whether it needs a database, and which folders survive a restart. blitz.cloud works these out by reading the image. If the port is wrong, you can change it under Advanced settings.
6. Give the app a Name and an address, then click Put it online.

You watch it go through its steps, and when it is done you get a link like https://whoami.lena.blitz.cloud. The certificate for your address is issued automatically; until it is ready, a browser can briefly show a certificate warning on a brand new account.

If nothing is ready yet, the app page says so in a sentence and shows the last lines the container printed. App status and logs explains each message.

Try it with a ready-made example

The blitz-cloud-examples repository has three small apps that follow the rules above: a Node.js API, an Astro site behind nginx, and a FastAPI app. Build one, push it to your Docker Hub account, and deploy it with the steps above:

git clone https://github.com/blitzworks-io/blitz-cloud-examples.git
cd blitz-cloud-examples/python-api
docker build --platform linux/amd64 -t yourname/blitz-example-python-api:1.0.0 -t yourname/blitz-example-python-api:latest .
docker push --all-tags yourname/blitz-example-python-api

What the free plan includes

A pasted image gets the small size: 128 MB of memory reserved and up to 512 MB when it needs more. That fits most APIs and small web apps. A JVM app with a big heap or anything that needs several GB of RAM is a bad fit for the free plan today. The full rules are on Limits.

Free Docker hosting compared

Most platforms that run Docker images have dropped their free plans or turned them into trials. This is what each one gives you for nothing today, from the providers' own pricing pages and docs, checked on 25 September 2026.

The detailed comparisons are on Render, Railway, Fly.io and Heroku. Sources: render.com/docs/free, railway.com/pricing, docs.fly.io/about/free-trial, heroku.com/pricing, cloud.google.com/run/pricing. Oracle Cloud also has an always-free tier, as a virtual machine you run yourself rather than a container platform.

When blitz.cloud is the wrong choice

If you need servers outside Europe, GPU access, private images or arm64, pick something else for now. If you want a container online in the EU for nothing, it fits well. And if the code is yours and lives on GitHub, you can skip the image: connect GitHub, pick the repository, and blitz.cloud builds every push. See deploy a GitHub project.