Let’s clear something up right away—yes, a Conex box and a shipping container are basically the same thing. But depending on who you’re talking to (and what you’re using it for), the name can matter.
A Conex box is just a type of shipping container. The term started with the U.S. military during the Korean War. They needed tough steel boxes to move supplies fast—and they called them “Container Express,” which eventually got shortened to Conex. That’s the Conex box origin.
A shipping container is the general term for those big, rectangular steel boxes you see on cargo ships, trains, and trucks. Sometimes called freight containers, sea containers, or ocean containers, they’re made to carry goods long distances and handle everything from wild ocean storms to forklift beatdowns.
So, why the different names? And does it really make a difference which one you use?
In this post, we’re going to walk through:
- Where the term Conex came from (and why it stuck)
- What makes these containers so strong and reliable
- The real differences (if any) between the two
- And how folks are using them today for portable storage, tiny homes, job sites, and more
Whether you’re shopping for one, renting, or just curious, you’re in the right place.
Key Takeaways
- A Conex box is just a shipping container with a name that started in the military.
- Both are built from rugged steel and made to handle rough weather, long trips, and heavy use.
- They come in standard container sizes like 20- and 40-foot and work great for storage, job sites, or even creative builds.
- At the end of the day, the only real difference is what folks choose to call them.
What is a Conex box, exactly?
A Conex box is just a tough steel container built to store and move stuff without a fuss.
The name comes from “Container Express,” which says it all—these things were made to handle fast, secure transport.Most come in two standard container dimensions —20 feet or 40 feet—so they’re easy to stack, load, and fit just about anywhere you need them.
The History of Conex Boxes
Conex boxes got their start during the Korean War, when the U.S. Army needed a tougher way to ship supplies to soldiers. This was the beginning of U.S. military containers.
Back then, freight containers containers were the norm, but they were easy to break into and didn’t hold up well. So the Army rolled out steel “Transporters,” which were sturdier, more secure, and way better for the job.
By the 1960s, shipping companies saw the benefit in standardizing sizes—this was a big moment in shipping container history. It made it easier to load containers onto trucks, trains, or ships and to stack them like giant building blocks. That’s where the modern ISO containers came into play.
What’s a Shipping Container?
Shipping containers (also called cargo containers or ocean containers) are standard-size metal boxes for transporting goods across sea, rail, and the road. They’re mostly made from Corten steel that doesn’t rust easily and can stand up to rough weather—ideal for use as durable containers on long trips. Furthermore, They have grooves in the metal that make them strong and not break easily. Shipping containers come in different sizes, but 20 feet and 40 feet ones are used the most.
The corners of these containers are extra strong, so you can connect them to other containers or hook them up to cranes to lift them. Unique slots on the bottom side let you move them with a forklift. Most are watertight containers, built to meet strict container specifications for sea-worthiness under the Convention for Safe Containers.
Features of Conex Boxes and Shipping Containers
To better understand the similarities between a Conex box and a shipping container, it’s helpful to look at their similarities.
Watertight
Most of the time, new containers are watertight and can keep water out entirely. A suitable container for the sea won’t let water in because it has unique rubber around the doors to block water and other stuff from getting inside.
Durable and Reliable
Containers are made strong to handle being moved across the ocean, so they last a long time, and you can count on them to complete the journey.
Size
Both of these containers come in 20-ft or 40-ft sizes. This means they can fit on most trucks or trailers without any trouble. It’s easier to take them to the seaport than bigger containers. On a ship, they can be moved around and stacked up well. The International Organization for Standardization determines shipping container designs and sizes.
Is There a Real Difference Between Conex Boxes and Shipping Containers?
Not really.
Conex box = slang term that started in the military.
Shipping container = industry standard term used worldwide.
They’re built the same way. They do the same things. The only real “difference” is the name—and where you hear it used.
Here’s a quick side-by-side:
Conex Box vs Shipping Container: Side-by-Side
| Feature | Conex Box | Shipping Container |
| Term Origin | U.S. Military (Korean War, 1950s) | Global shipping & logistics industry |
| Meaning | Short for “Container Express” | General term for intermodal containers |
| Materials | Usually Corten steel or similar | Corten steel (weather-resistant) |
| Common Sizes | 20 ft and 40 ft | 20 ft and 40 ft |
| Primary Use | Military, storage, job site use | Shipping goods across sea, rail, road |
| Waterproof? | Yes, with rubber door gaskets | Yes, sea-worthy with proper seals |
| Stackable & Forklift Ready | Yes | Yes |
| Name Usage | More common in U.S. & construction | Standard term used globally |
Ways to Use Conex Boxes and Shipping Containers
These days, shipping containers/Conex boxes are for more than just shipping. People use these containers for lots of different things, including:
- Shipping goods over sea or rail
- Warehouse storage (equipment, tools, goods)
- Additional home storage
- On-Site storage
- Container Homes, commonly known as ‘tiny homes’
- Container offices
- Emergencies (temporary shelters or medical facilities)
- Pop-up shops, bars, or exhibition stands
Which Container Should You Choose?
Choosing between a Conex box or a regular shipping container is straightforward. It all comes down to how much stuff you have, how heavy it is, and how many containers you need. Use a Conex box if you’re shipping small goods requiring only a little room or extra protection. If you have many large items that aren’t that heavy, consider whether a 20-foot or 40-foot shipping container is right for you. Still not sure which container’s right for your setup? We’ll help you pick the right one, just reach out.
Conclusion
Shipping containers have significantly changed how we handle logistics and design buildings. These large metal containers do more than move goods now; they’re critical to both fields for their flexibility and toughness. Shipping containers are unmatched in meeting today’s complex shipping needs and construction. Businesses and homeowners have reused them for different needs, like storage or building cutting-edge homes. Looking ahead, these containers will keep leading the way, showing us how to use materials smarter and build a future full of new possibilities.
