There's no doubt about it: Charlotte's Web is written primarily for young folks. We know this just by looking at our cast of characters. When you have lots of growing animals and a couple of kids taking up most of the story, you can bet the book is of the young adult sort. Of course, this doesn't mean adults don't enjoy this book too. (Just ask Shmoop.)
And that brings up another genre for us: Charlotte's Web is a coming-of-age tale. This means that it tracks the characters as they grow from childhood to maturity. Often, coming of age novels cover years and years, so you actually see kids grow up to become full-fledged adults. But in Charlotte's Web we get just a peek into one year of our characters' lives as they grow older. (There's tons to say about growing up in Charlotte's Web. Head on over to the "Coming of Age" theme for more tidbits.)
One last thing: for Wilbur, growing up means going on a journey. And that makes this novel fits into the quest genre. Actually, we think Wilbur goes on two quests in this tale: a traveling journey and a personal journey. He goes to the County Fair, which is a super important trip for our little piggy friend. Plus, he has to overcome his fear of dying and learn to rely on his friends. That makes the journey even sweeter.