3 Dockerfile Generators, Compared Honestly

Your first Dockerfile works. It is also 1.2GB, rebuilds from scratch every time you change a line of source, and runs your application as root.

None of that is obvious from a file that builds successfully, which is why generated Dockerfiles are more useful than they sound. The specific improvements are well known — multi-stage builds so compilers do not ship to production, dependency files copied before source so the cache survives, a non-root user, a .dockerignore — and they are exactly the things people leave out when writing from memory.

How to judge a Dockerfile generator

Does it do multi-stage? Build tools stay in the first stage, only artefacts move to the final image. This is the single largest size and security win available.

Does it order layers for caching? Copy the lockfile, install dependencies, then copy source. Get that backwards and every source edit reinstalls everything.

Non-root by default? Containers run as root unless told otherwise, and almost nothing needs it.

Does it produce a .dockerignore? Without one you are copying node_modules and .git into the build context every time.

The comparison

Facts checked August 2026; tools change their plans. Table covers only the 3 alternatives — our tool gets its own section below.

Devsly

The only one here that checks its own output. It generates production-ready Dockerfiles for Node.js, Python, Go, Java, PHP, Ruby, .NET and Rust with multi-stage builds and security hardening, then runs an automatic security scan flagging hardcoded secrets, excessive permissions and insecure practices.

Optional extras cover non-root users, health checks, BuildKit cache optimisation and automatic Docker Compose generation — the compose output being a genuine time-saver when the service needs a database next to it. Completely free with no registration or payment. The scanner is a linter rather than an oracle; treat findings as prompts.

8gwifi Dockerfile Generator

The most opinionated starting points. Beyond Node.js, Python, Go, Java, .NET, Rust and custom base images, it ships presets — Node.js (Production), Python ML, Go (Minimal), Java Spring — which get you further than a blank form because someone has already made the sensible choices for that stack.

It produces the .dockerignore and the Docker commands alongside the Dockerfile, and covers Alpine and slim images, version pinning, health checks, layer optimisation and metadata labels. Free, no account, with an optional donation. The interface looks like a utility from a decade ago, which matters not at all.

EaseCloud

The most private and the most pared back. It generates for Node.js, Python, Go, Java, PHP and Ruby applying multi-stage builds, layer caching optimisation, security hardening, non-root users, minimal base images and Alpine options — the standard best-practice set, applied without ceremony.

All processing happens client-side, so your application configuration stays on your machine. It offers fewer switches than the other two, which makes it faster to use and less suited to an unusual setup. Free, no account needed.

Dockerfile Builder

Ours assembles a Dockerfile with multi-stage builds, a non-root user, correct layer ordering and a .dockerignore that keeps the image small. Layer ordering being called out explicitly is deliberate: it is the least visible of the four, it costs you minutes on every rebuild when wrong, and no error message will ever tell you about it.

What it does not do: security-scan the result, generate a Docker Compose file, or offer per-framework presets. For a stack with unusual needs, 8gwifi’s presets or Devsly’s scanner will get you further. Docker’s own multi-stage documentation is worth reading once properly — it is short, and it explains why the pattern matters rather than just how to type it.

Which one to pick

• A Dockerfile you want checked as well as written — Devsly.
• A preset for a specific stack, plus compose or ignore files — 8gwifi.
• Config that must not leave your machine — EaseCloud, or the tool below.
• The four fundamentals, correctly ordered — the tool below.

How to do it with Dockerfile Builder

1. Open the Dockerfile Builder and pick your runtime and base image.
2. Enable multi-stage — for compiled languages this alone can remove most of the image size.
3. Check the layer order: dependency manifest, install, then source.
4. Take the .dockerignore as well; without it the build context includes everything you did not want.

The walkthrough is in how to write a Dockerfile that builds fast. Other developer tools are in the tools directory.

You might also need

The GitHub Actions Workflow Builder covers building and pushing the image in CI.

Run the Secret Scanner over anything going into the build context — secrets baked into a layer stay in the image even if a later layer deletes them.

Frequently asked questions

Is there a free Dockerfile generator that doesn’t need an account?

All four here are free with no account. EaseCloud and ours process client-side; Devsly and 8gwifi are free with no registration and add scanning and presets respectively.

Why is my Docker image so large?

Usually because build tooling ships with it. A compiler, dev dependencies and package caches can be several times the size of the artefact you actually need. Multi-stage builds fix this by copying only the output into a clean final image.

Why does every build reinstall all my dependencies?

Layer ordering. If you copy your whole source tree before installing dependencies, any source change invalidates the cached install. Copy the lockfile and manifest first, install, then copy the rest.

Final thought

Fix the layer order before optimising anything else. It costs nothing, it is invisible in a working build, and it is the difference between a five-second rebuild and a five-minute one for the rest of the project’s life.

Try the free Dockerfile Builder