Online jigsaw puzzles for adults vary in difficulty. Puzzle websites typically offer a range of puzzles that may include easy ones with just a handful of pieces, very difficult ones with several hundred pieces, and puzzles of average difficulty that fall between these extremes.
JigZone.com offers puzzle sizes ranging from six to 247 pieces, as of early 2015. The site offers a daily puzzle of the day, and it allows users to upload their own images to create and share custom puzzles.
Jigsaw Planet's homepage displays a large number of puzzles and shows how many pieces each one has. Users can select a puzzle without signing in. The site encourages users to create puzzles from their own images and enter them into a weekly competition.