---
title: "What is the difference between ADD and COPY in a Dockerfile, and when should each be used?"  
description: "What is the difference between ADD and COPY in a Dockerfile, and when should each be used?"  
author: "Pedro Araez"  
published: 2026-09-30  
canonical: https://answers.mindstick.com/qa/117322/what-is-the-difference-between-add-and-copy-in-a-dockerfile-and-when-should-each-be-used  
category: "Docker"  
tags: ["docker", "Dockerfile", "DevOps", "Containerization", "Interview Questions"]  
reading_time: 1 minute  

---

# What is the difference between ADD and COPY in a Dockerfile, and when should each be used?

While reviewing common Dockerfile questions for a developer position, I noticed that interviewers often ask about the distinction between the `ADD` and `COPY` instructions. In many basic examples, both commands seem to perform the exact same action of placing files into a container image.

Consider this example snippet from a sample build script:

```dockerfile
# Copy local file into the container filesystem
COPY app.tar.gz /tmp/app.tar.gz

# Extract local tar archive automatically into the container destination
ADD app.tar.gz /tmp/app/

# Fetch remote file from a URL during build time
ADD https://example.com/config.json /etc/config.json
```

I want to understand the precise operational differences between these two commands so I can answer confidently in an interview context. Specifically, I am trying to break down:

- What additional capabilities does `ADD` possess over `COPY` (such as auto-extraction or remote URL downloading)?
- Why do official Docker documentation and security guidelines generally favor `COPY` for standard local file transfers?
- Are there edge cases where using `ADD` is actually recommended, or is it considered bad practice in modern container builds?


---

Original Source: https://answers.mindstick.com/qa/117322/what-is-the-difference-between-add-and-copy-in-a-dockerfile-and-when-should-each-be-used

Copyright © MindStick Software Pvt. Ltd. This Markdown version is provided for developers, AI systems, and offline reading.