Dockerfile vs. Docker Compose: What's the Difference?

Though both are elements of the application management tool Docker, Dockerfile vs. Docker Compose have very different use cases. Which one (or both) you need depends on how many moving parts your project has – you'll see the split below.

In this guide, you'll see what each file actually does, a working example showing where they overlap and where they don't, and how a Compose file and a Dockerfile typically end up in the same project together.

What is a Dockerfile?

A Dockerfile is a simple text file that lists the instructions Docker needs to build a Docker image – which base image to start from, which files to copy in, which dependencies to install, and which command to run when a container starts. Each instruction adds a layer, and Docker builds those layers in order.

Here's a minimal Dockerfile for a small Node.js app:

FROM node:20-alpine

WORKDIR /app

COPY package*.json ./

RUN npm install

COPY . .

CMD ["node", "server.js"]

When you run docker build -t my-app ., Docker reads that file, builds an image, and tags it my-app. That image is a reusable template. Run docker run -p 3000:3000 my-app, and you will get a running Docker container from it.

A Dockerfile just builds one image. It doesn't run anything by itself, and it doesn't have any information about other containers your app might need.

What is Docker Compose?

Docker Compose solves a different problem: running multiple containers together without typing out a long list of docker run flags by hand. You describe every service, its image or build source, its ports, and its environment variables in a single YAML file, usually named docker-compose.yml or compose.yaml, saved in the same project folder as your Dockerfile.

Here's a small example with a Node.js app and a MySQL database:

services:

  app:

    build: .

    ports:

      - "3000:3000"

    environment:

      - DATABASE_URL=mysql://user:password@db:3306/myapp

  db:

    image: mysql:8.0

    environment:

      - MYSQL_ROOT_PASSWORD=example

      - MYSQL_DATABASE=myapp

      - MYSQL_USER=user

      - MYSQL_PASSWORD=password

    volumes:

      - db-data:/var/lib/mysql

volumes:

  db-data:

Run docker compose up, and both services start with a single command, connect over a shared network Compose creates automatically, and read their settings from the file instead of a list of flags you'd otherwise have to remember and retype.

The key difference between a Dockerfile and Docker Compose

Once you compare both next to each other, the split is obvious: a Dockerfile builds a single Docker image, while a Docker Compose file defines and runs multiple services from images – images that are often built from a Dockerfile.

As you can see from this table, these two tools solve different problems at different points in the process.

Neither file replaces the other. A Compose file that builds a service still needs a Dockerfile (or a ready-made image) to build it from, and a Dockerfile has no concept of a second container, a shared network, or a volume.

When to use a Dockerfile vs. Docker Compose

Which one you use depends on how many moving parts your app has and where you are in your Docker journey.

Single-container apps and custom images

You'll be able to make do with a Dockerfile on its own when you're packaging one application into a portable image with no other services to coordinate. If you're building an image to push to a registry, or running one container standalone on a host, you don't need a Compose file at all.

Multi-container applications

Once your app needs a database, a cache, or a background worker alongside the main service, it's time to consider using Compose.

For these more complex setups, Compose replaces a growing list of manual docker run commands and network setup with one file and one command, and keeps those configurations in version control alongside your code instead of scattered across a README.

Using a Dockerfile and Docker Compose together

Most real projects use both, rather than picking one file over the other, with the Compose file pointing at the Dockerfile for the services it needs to build:

services:

  app:

    build:

      context: .

      dockerfile: Dockerfile

    ports:

      - "3000:3000"

  cache:

    image: redis:7-alpine

Here, the app service builds from the Dockerfile in the current directory, while cache pulls a ready-made Redis image straight from a registry instead of building one.

Compose treats a build source and a pre-built image the same way once both containers are running, and this setup – one or more services built from a Dockerfile, others pulled as images – covers most multi-container configurations you'll likely need.

How Dokploy handles Dockerfiles and Compose files

Dokploy mirrors the split as two separate ways to deploy a project. An Application service can build directly from a Dockerfile in your repository, as one of several available build types alongside Nixpacks (the default), Railpack, buildpacks, and a Static option for pre-built sites.

A Compose service, on the other hand, takes an existing docker-compose.yml from your repository and deploys it largely as written, with Dokploy managing environment variables, volumes, logs, and monitoring for each service inside it.

To choose between these two options, ask yourself if you are deploying one containerized service or several that need to run together.

If your project already has a Dockerfile and no Compose file, an Application service handles it without you writing a Compose file just to deploy. If you already maintain a docker-compose.yml for local development, a Compose service can deploy that same file with far fewer changes than migrating to a different format.

Conclusion

The question of Dockerfile vs. Docker Compose isn't really a competition once you see what each one is responsible for. A Dockerfile builds a Docker image. A Compose file runs one or more containers from images, coordinating the services, networks, and volumes between them.

Most projects past the single-container stage end up using both, with Compose calling out to a Dockerfile for the services it needs to build.

If you're at the point where you're managing more than one containerized service, Dokploy can deploy either file type directly from your repository, handling builds and environment variables without a separate deployment script, with HTTPS support built in.

Sign up and connect a repository to see how your existing Dockerfile or Compose file deploys.

Dockerfile vs. Docker Compose FAQs

Can you use Docker Compose without a Dockerfile?

Yes. A Compose file can reference ready-made images from a registry for every service instead of building any of them, in which case you don't need a Dockerfile at all. You only need one for services you're building from your own source code.

Do you need a Dockerfile if you already have a Docker Compose file?

Only for the services you build yourself. If every service in your Compose file uses an image: reference to a published image, like a database or cache, there's no Dockerfile involved for those services. Your own application code usually still needs one.

Is Docker Compose only for local development?

No, though that's where it's most commonly introduced. Compose files run the same way in production as they do locally, and plenty of small to mid-sized deployments run a Compose file directly on a server.

Larger, multi-host deployments typically move to container orchestration or a deployment platform once a single host and Compose file stop being enough.