W3Schools is optimized for learning, testing, and training. Examples might be simplified to improve reading and basic understanding. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content
W3Schools Will Always Be Free
In 1998, our company - Refsnes Data - made a very controversial decision. We decided to quit our current jobs and start an Internet Developers Portal.
When we created W3Schools, we wanted it to be completely free, and we are doing our best to keep it that way.
The costs of running this site and the costs of writing the tutorials are covered by sponsors, but we will always try to keep the number of advertisements as low as possible.