WordPress GPL Licensing
What the GPL Means for WordPress
The WordPress GPL license is the GNU General Public License, version 2 or later, under which WordPress core is released. The GPL is a copyleft license: anyone who distributes a modified version must pass the same freedoms on to recipients. Those freedoms include using, studying, modifying and redistributing the software.
Themes and plugins run inside WordPress and use its code. The WordPress project takes the view that they are derivative works, and its directory guidelines require the plugins and themes listed there to be GPL-compatible. This is why most free WordPress themes and plugins are released under the GPL. How open-source and proprietary software compare more broadly is covered in the open-source comparison article.
Can Premium Themes and Plugins Be Sold?
Yes, according to the WordPress project’s position. The GPL does not forbid charging money for software; it requires that recipients keep the freedoms the license grants. Many premium developers sell GPL-licensed products and charge for support, updates and convenience features.
Some developers use other licenses for parts of their products, or add terms of sale such as license keys that unlock updates. Whether a particular product’s terms are enforceable is a legal question, and this article does not give legal advice. The differences between free and paid products are covered in the free vs premium themes article.
Nulled Themes and Why Licensing Terms Matter
A nulled theme or plugin is a premium product whose license checks have been removed and which is shared for free, usually outside the official vendor channel. Vendors commonly say that such copies breach their terms of sale. Even where the underlying code is GPL, removing a license check can conflict with the seller’s terms, which is the licensing concern.
Nulled copies are also a frequent source of security problems. Those risks are outside the scope of this article.
Frequently asked questions
Is every WordPress theme and plugin free under the GPL?
Not necessarily. Most WordPress themes and plugins follow the GPL, but some developers sell or license products on terms beyond it, and parts of a product may carry different licenses. Check the license file or product page before assuming the terms.
Does the GPL mean WordPress costs nothing to use?
The GPL concerns the software’s freedoms rather than its price, and WordPress itself can be downloaded and used at no charge. Costs come from elsewhere, such as hosting, domains, premium products and developer time. The full list of costs is explained in the is WordPress free article.