Best Free Online Developer Tools to Use in 2026
A practical, opinionated list of the best free online developer tools worth using in 2026, organized by category so you can find what you need fast.
Aug 08, 2026
Dockerignore Generator
Generate .dockerignore files with optimized exclusion patterns for your project type.
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Select a project type to see a .dockerignore template.
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What is a .dockerignore File?
A .dockerignore file works like .gitignore but for Docker builds. It specifies files and directories that should be excluded from the Docker build context. This reduces build context size, speeds up image builds, and prevents sensitive files from being included in the image.
This generator creates optimized .dockerignore files for common project types. Each template is tailored to exclude language-specific build artifacts, dependencies, caches, and development files that shouldn't be part of your Docker image.
How to Use
- Select Project Type — Choose your project language or framework from the dropdown.
- Toggle Options — Enable or disable additional ignore patterns like Docker files, git files, environment files, and editor files.
- Preview — The generated .dockerignore updates in real time as you change selections.
- Copy or Download — Use the copy button or download the
.dockerignorefile and place it next to your Dockerfile.
Frequently Asked Questions
Why do I need a .dockerignore file?
Without a .dockerignore, Docker sends the entire build context (all files in the directory) to the Docker daemon. This slows down builds, increases network transfer, and may accidentally include sensitive files like .env, SSH keys, or development caches in the resulting image.
Should I include node_modules in .dockerignore?
Yes, if you install dependencies inside the Docker container using a RUN command. Including node_modules in the build context is unnecessary because they will be installed fresh during the build. This follows best practices for Docker image layering and caching.
What is the difference between .gitignore and .dockerignore?
.gitignore prevents files from being tracked by Git. .dockerignore prevents files from being sent to the Docker build context. They often share similar patterns (node_modules, .env, build output) but serve different purposes. It's recommended to keep both files if you use Docker.
Is my data stored?
No. Everything runs entirely in your browser. Your data is never sent to any server.
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