worldwide vs. international

Use worldwide to describe something that encompasses all regions or involves the entire world. It's OK to use global to mean worldwide.

Examples
Get one month of free, worldwide calling.
OneNote Mobile for Android is now available in more than 20 markets worldwide. Ensuring global acceptability in the usability of our products along with local relevance (world readiness).

Don't use international in the context of something that encompasses the entire world as it can imply a US-centric worldview.

Don’t use international to mean “outside the United States.” Instead, refer to a specific region or use wording that describes what you mean.

Examples
In the first half of 2016, Azure achieved new certifications in Japan, Spain, and the United Kingdom and expanded certifications in seven other regions. Microsoft is driving the transformation of business and industry across Europe and around the world.

See also global