The GPL and the Legal Limits of What You Can Do with Blender

Aug 8th 2023

It is common knowledge that Blender is free, but not everyone is aware that it didn't start out that way or how its current license, the GPL, affects what one can and cannot legally do with the software. At CG Cookie, Blender Market, and Orange Turbine, our livelihoods are directly dependent on Blender's license. Therefore, it is safe to assume that we understand it well and have some thoughts on the subject.

This post is from episode 3 of the Denoise podcast. Listen on iTunes, Spotify, GoogleAmazon, and wherever else you find your podcasts.

  1. Blender wasn't always free.
  2. Free and open source.
  3. What if Autodesk or Adobe buys Blender?
  4. What you create is truly yours.
  5. The downsides of GPL.
  6. The gray area of add-ons.
  7. What about Blender pirates?

Blender Wasn’t Always Free

Blender was born in the Netherlands on January 2nd, 1994, when its creator, Ton Roosendaal, coded the first lines of what would become a tool used by millions. At the time it was first made available, Blender wasn’t open-source. There was a free version with basic features, but users had to purchase a key to unlock its full power. However, despite many interested users and two successful rounds of venture capital funding, Blender didn’t quite make a profit and Ton’s company behind it, NaN, had to shut down.


The license to Blender belonged to NaN’s investors, and Ton did not have enough money to purchase it back. So, instead, he offered its users a deal - if they came together and paid for the rights, they could all collectively own it under an open-source license. 250,000 people chipped into that campaign and Blender became free from then on.

It’s no wonder why Blender’s user base is passionate and vocal - they bought it! It’s theirs! The community has a sense of ownership and responsibility that just doesn’t come about otherwise.


Unreal Engine became free in 2015, almost 20 years after Blender

Being free was an even bigger deal back then since its competition was a few thousand per year, and game engines like Unity and Unreal weren’t yet free to use until much later. Blender’s success likely is what pushed those other apps to lower their prices and, in some cases, adopt the freemium business model that makes them so accessible today.

Free and Open Source

Even though many other apps like Unity, Unreal, Resolve, etc. all have free to use versions, what you are allowed to do with them vs. what you are allowed to do with Blender are drastically different. The license that was chosen, the GNU General Public License (a.k.a the GPL), is an interesting one that sets Blender apart from other free or open-source applications that you may have used.

Blender being open-source is not the same as its being free to download. The creator of the GPL refers to the “free” aspect of open source as “free as in freedom, not free as in beer”. I.E., the users have a right to use the software how they’d like, but it doesn’t necessarily mean they can get it without paying. The Blender Foundation could charge for officially sanctioned downloads or updates, but it chooses not to.

Anyone with the software can change it for their own purposes, redistribute it to others, and see the source code if desired. The only catch is that if they distribute anything that includes part of the original program, they must do so under the same GPL license.

Other licenses such as MIT or Apache are considered more permissive because they have less strict requirements on what license you can redistribute the program under. As with everything, that has some tradeoffs. If Blender was under the MIT license, any big company could take Blender, add a feature, and then sell it as closed-source proprietary software. The hundreds of developers who have volunteered to improve Blender would see all their work only benefiting someone else and Blender itself could easily fall behind its commercially funded counterparts.

However, since Blender is under the GPL, any improvement made to Blender must be open source, so new developments by individuals or companies can always be incorporated back into Blender for everyone’s benefit. In a big way, the GPL is about protecting the developers, which is exactly why so many people volunteer to work on it.

Many founding developers have mentioned that if it wasn’t for that protection, they would have considered working on Blender a waste of time and may not have contributed.

If Blender wasn’t under the GPL, it very likely wouldn’t exist.

What if Autodesk or Adobe buys Blender?

Adobe bought Figma not that long ago and it left us wondering - will our files get locked behind a new subscription paywall? Will they change the app for better or for worse? Companies get acquired all the time, even if their app is free to use, often because of the size of their user base. Sometimes those apps get improved, but sometimes they get bloated, run into the ground, or shut down entirely.


Softimage shut down in 2015 after Autodesk's purchase 

Interestingly, the GPL is exactly what prevents that from ever being a concern for Blender. Since the code itself cannot be used in another program that’s not licensed under the GPL, even if a company purchased the entire Blender Foundation, they couldn’t do much with it.

If they added bloat, someone else could freely rip it out and distribute a cleaned version. If they tried to kill development or charge too much for it, volunteers could pick it up at any point and distribute it for free. The only way to change Blender to any other license other than the GPL would be to get written consent from every single person who has ever written a line of its code - and that’s just not going to happen. Blender is going to be free forever.

Read the Blender credits:

What You Create is Truly Yours

It’s important to note that the GPL extends to anything that includes Blender source code but does not apply to the outputs of Blender. Anything you create with Blender, whether that be an image, a 3D model, a video, or even a blend file, is yours (or the company’s that you’re working for) by default. Artists can safely use Blender without worrying about anyone legally being able to copy or distribute their work.

The same cannot be said of many other free tools. Most free software that is not open source has some clause in the agreement about its company having the right to use your work for whatever purpose they see fit or placing limits to what you can do with what you create. They can also choose to cut off your access to the program at any time, which would leave you unable to open your own work. With Blender, anything you create is entirely owned by you.

The Downsides of the GPL

The GPL license isn’t without its drawbacks. Because any program that uses the Blender source code must also itself be GPL, many of the add-ons that users might wish for are not developed.


Finally, a Substance add-on for Blender

For example, it took ages for Blender to get a Substance add-on because there was no way in h*ck that its creator, Allegorithmic (now under Adobe), was going to open source its Substance engine in order to connect it to Blender. They managed to dodge the licensing issue, but it took years for Blender users to get what Maya and Unreal users had right away. For the same reason, Houdini conveniently plugs in to other apps like Maya and Unreal, but specifically not Blender. This lack of compatibility with the other leading apps can be a real hit to using Blender in some studio pipelines.

Also, most big studios develop custom tools for their productions that they don’t want to open source. If they developed those tools on top of Blender, they might have to give away their trade secrets for free, which they may not see as being in their best interest. Technically, they don’t have to open source the tools if they don’t distribute them outside of the company, but defining what legally counts as distribution (what about giving them to a contractor? What if the contractor is logging in to a remote workspace and no files are sent?) is a bit tricky.

The Gray Area of Add-ons

As mentioned before, anything that contains a part of Blender’s source code must also be open-sourced under the GPL. Every Blender add-on starts with `import bpy` to import Blender’s Python API into the script, thus bringing a part of Blender’s code into the project. This link is why Blender add-ons must also be GPL. Seems pretty clear cut, right?

What makes matters a little more complicated is that many add-ons are not just code but a mixture of code and assets. Remember, anything you make with Blender is yours by default and assets made with Blender can be copyrighted. So, if an add-on contains a library of assets, what is its license?


Many popular add-ons are a mix of code and assets

The best solution is to consider it as two separate parts: the add-on, which is code and under the GPL, and the assets which are whatever license the creator has determined. So, if you purchase an add-on that scatters models, you’re free to distribute, copy, modify, or do whatever you want with the code, but you may not be able to do those things with the models. Copying and distributing both at the same time would therefore be prohibited.

But what if the models are needed for the script to run without error? Is it then part of the program? What about custom icons? What if the icon is a logo? As you can see, diving too deep into specifics opens up a whole can of worms. So, to keep things simple, our policy is:

  • Blender add-on code is GPL
  • Assets are licensed separately 

It’s also possible for Blender add-ons to act as a bridge to other software and talk to external programs that don’t have to be GPL compatible, which is how the Substance add-on works. This often means installing that program separately, though, which can be an inconvenience for users.


Another complicating factor is that the United States, the EU, the UK, China, Japan, and many other legal systems all have slightly different laws as to the copyrightability of APIs. In the US, after the Google vs. Oracle case, it’s very unclear whether or not someone claiming copyright of an API would hold up in court.

For the time being though, it’s safest to assume that using the Blender API means that the code of any add-on needs to be GPL as well.

If you'd like to read more about the GPL then we have several other articles to get you started.

Blender Pirates?

Because the waters surrounding add-ons are a bit murky, different commercial add-on creators take different approaches to distribution. Some give their add-ons or assets away for free and just ask for donations, while others try as hard as possible to limit the use of add-ons that were not purchased from them directly.

We’ve talked about our stance on piracy when it comes to Blender add-ons before. If an add-on is entirely GPL code, there is no such thing as piracy since it can be legally shared by anyone. Someone taking and using your assets without permission, however, is considered not cool and not legal.

It's important to note that downloading an add-on or asset directly from the creator is itself a valuable thing - not just to support them but also to keep yourself safe. Downloading .zip files from potentially sketchy websites or Discord servers is generally not a great idea, and we've had plenty of reports of viruses being bundled with add-ons when distributed in that manner. 


That said, piracy is impossible to stop. If Adobe, Autodesk, HBO, Disney, etc., can’t do it, neither can you.

The amount of work it takes to do anything effective against pirates is immense, and that time will always be better spent on marketing and improving the tool. Also, anti-piracy and digital rights management (DRM) measures often worsen the user experience for legitimate customers.

At the scale we're working at in the Blender world, spending time getting new customers and making existing users happy is more effective than worrying about losing low-quality potential customers.


Blender being under the GPL means that you can use it to create whatever you’d like, what you create with it is entirely yours, and it’s impossible to stop Blender from being free.

If you work with or are considering working with Blender professionally and have questions about the GPL, don’t hesitate to reach out to us at CG Cookie's sister company, Orange Turbine. We help businesses work smarter by using Blender and would be happy to help you out.


Jonathan Lampel
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