Our daily crossword competitions are done on paper, but there are many options online for people who also like crosswords, and some of them are free. Here's a smattering of the choices available. Note: if you're unfamiliar, some of these look like videos, and there may be an ad at the beginning, but the crossword will follow.
Click through to the puzzles at the links below:
Merriam-Webster Daily Crossword
The Washington Post
The L.A. Times
AARP (and no, you don't have to be a senior or a member to play)
The New York Times crossword is, of course, the gold standard for crosswords, but it's not free (at the moment the monthly rate is $6.95 or $39.95 for a year). Also, it's really challenging and I'm not always up to the challenge (in the past, I've owned books of the New York Times Sunday crosswords).However, the paper also offers a daily mini (usually just 5 x 5) and that one is free. As it's timed, I enjoy trying to solve it in less than a minute. Sometimes I succeed. Other times...well, I still enjoy trying.
The New York Times mini crossword
Also, this page has some archives of the mini (the other one might, but I wasn't sure).
This, of course, is just a smattering of the puzzles out there (although I think these are some of the best). So if you're a crossword enthusiast, enjoy!