I'd like to emphasise something really basic, though: a "webfont", technical implementation details aside, is a font you've been licensed, by its creator or a rights holder for the specific task of using on a website. And those will come in a webfont format. If you're sitting in front of a generator to convert a font to a webfont format and it's not open-source or one you drew yourself, stop right there! You're almost certainly breaking the license and could get sued. And since it's on the web, it's easy for people to find what you're doing and check against their list of sales.

See e.g. this doofus, who has done work for Facebook and Google, who didn't realize until someone told him that he was technically using a pirated font on his website. He had a desktop subscription license, but that isn't a license for web use.

I'd like to emphasise something really basic, though: a "webfont", technical implementation details aside, is a font you've been licensed, by its creator or a rights holder for the specific task of using on a website. And those will come in a webfont format. If you're sitting in front of a generator to convert a font to a webfont format and it's not open-source or one you drew yourself, stop right there! You're almost certainly breaking the license and could get sued. And since it's on the web, it's easy for people to find what you're doing and check against their list of sales.

See e.g. this doofus, who has done work for Facebook and Google, who didn't realize until someone told him that he was technically using a pirated font on his website. He had a desktop subscription license, but that isn't a license for web use.