So You Want to Build a Virtual Try-On App? (A Developer's Guide to Not Getting Sued)

Every few months, a new open-source model drops on GitHub, promising more realism, better detail, and faster speeds. For a developer or an aspiring entrepreneur, it feels like a gold rush, a treasure trove of code just waiting to be turned into the next big feature for an e-commerce brand.

But hold on. Before you take that shiny new model and build a business around it, you need to have a little chat about licenses.

Think of a software license as the legal "terms and conditions" attached to the code. It’s the creator of the model telling you exactly what you can and, more importantly, cannot do with their work. In the VTON world, most models fall under a few key license types. Getting this wrong isn't a hiccup; it can put your project or business in legal jeopardy.

Let's break it down, no law degree required.

"NC" (The Non-Commercial Clause)

If you learn only one thing from this article, let it be this: if you see "NC" in a license, you cannot use that model to make money. Simple.

Most of the popular open-source VTON models you've seen, StableVITON, OOTDiffusion, CatVTON, IDM-VTON, VITON-HD, and HR-VITON, use a Creative Commons license with this "Non-Commercial" (NC) clause.

The most common one you'll encounter is the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (CC BY-NC-SA 4.0).

Let's translate that alphabet soup:

• BY (Attribution): You must give credit to the original creators. Think of it as citing your sources. If you use their model in a research paper or a personal project, you need to link back to their work and acknowledge them. It’s simple courtesy and a legal requirement.

• NC (Non-Commercial): This is the deal-breaker for business. It means you cannot use the software for any purpose that is "primarily intended for or directed toward commercial advantage or monetary compensation."

  • What this means for you: You can't build a Shopify plugin with it and sell it. You can't offer it as a paid service to brands. You can't even use it in a "freemium" model where the core feature is free but you have paid tiers. If money is changing hands as a result of the model's use, you're likely violating the license.

• SA (ShareAlike): This is the "pay it forward" clause. If you take the model and modify it to create something new (a derivative work), you must release your new creation under the exact same CC BY-NC-SA 4.0 license. You can't take their open, non-commercial work, tweak it, and then make your version closed-source or commercial.

A visualization explaining the different licenses. Source

These NC models are fantastic for academic research, personal experiments, and learning. They are not for building a business.

"I Trained It From Scratch, So I'm Safe, Right?"

This is one of the most common traps in the VTON world. You might think, “I’m not using anyone else’s code. I wrote my own model from scratch, so I’m free to use it however I want.”

Not so fast.

Even if all your code is original, you are still bound by the licenses of the datasets you train on. Two of the most widely used VTON datasets, VITON-HD and DressCode, are strictly non-commercial.

• VITON-HD is released under the Creative Commons Attribution-NonCommercial 4.0 International License. You can experiment, research, or publish academically, but you cannot use models trained on it for any commercial purpose.

• DressCode has a license from Yoox Net-a-Porter that is similarly restrictive. It allows use only for academic research, teaching, and publication, and it forbids commercial applications or modified redistributions.

If your model was trained on either of these datasets, or on any other non-commercial dataset, the resulting weights are still tied to those terms. It does not matter how original your code is. The dataset license still applies, and using the model commercially could put you in violation.

The only way to have a clear path for commercial use is to train on data you have the legal rights to use. This could be your own proprietary dataset, a licensed commercial dataset, or an open dataset with a permissive license.

Permissive Licenses

So, are you out of luck? Not at all! A few gems in the VTON space use "permissive" licenses, which are designed for commercial use.

MIT License (Used by DCI-VTON)

If you see the MIT license, you can breathe a sigh of relief. It’s one of the most simple and permissive licenses out there. It lets you do almost anything, including sell your work. Your only real obligation is to include the original copyright and license notice in your software.

That’s it.

DCI-VTON is a powerful model, and its MIT license makes it a very attractive starting point for a commercial project.

Apache 2.0 License (Used by ViViD)

The Apache 2.0 license is another fantastic, business-friendly license. It includes an express patent grant, which protects you from patent lawsuits from the contributors. If you modify the code, you must include a notice stating that you changed the files. ViViD, being a cutting-edge video try-on model, is a huge deal for anyone looking to commercialize video VTON, and its Apache 2.0 license is what makes that possible.

Real-World Scenarios

Anna is excited by CatVTON. She builds a brilliant web app for boutiques to use on their websites. When she tries to charge a monthly fee, she gets a cease-and-desist letter because she violated the "NC" clause. Her project is dead in the water.

Ben sees that DCI-VTON has an MIT license. He builds a similar service. He can legally charge brands a monthly fee. His only task is to make sure the original MIT license text is included somewhere in his product's documentation. Ben's business is on solid legal ground.

Are You Safe to Build Your Business?

Things to look out for before starting your commercial VTON project

Before you write a single line of code, you must do this. First, find the LICENSE file in the model's GitHub repository. This file is your single source of truth. Scan it for the letters "NC." If you see "Non-Commercial" and your goal is to make money, stop and find another model. Instead, look for "MIT" or "Apache" licenses. These signal you're on the right track for a commercial project. If you're ever in doubt, just ask. The creators are often accessible through GitHub issues, and some may even offer a separate commercial license for a fee.

The open-source community provides an incredible launchpad for innovation, but it operates on a foundation of trust and respect for the rules. By understanding these licenses, you can build amazing things while respecting the creators who made it all possible.

Your superpower, now, is the ability to tell the difference. You can look past the hype of a new model and ask the single most important question for your project: "What does the license really allow?"

If you want to skip the headache, you can build with FASHN’s API, home of the world's fastest commercially permissible Virtual Try On Model.