Holiday shoppers with a tablet computer on their gift list this year might be forgiven for feeling a little panicked.
Look at the tablets available online or at a consumer electronics store and it can be dizzying to choose from among the dozens of slim rectangles with touch screens — each with various sizes, features, prices and applications.
Tablets were supposed to be a simple alternative to the bloated personal computer market. And when "tablet" was synonymous with "iPad," that was true.
But this is the first holiday season in which the iPad faces competitors that have built up a solid footing in the market. Amazon and Google introduced tablets just in time for the shopping rush. As a result, many consumers and analysts say, the new market of keyboardless computers is quickly becoming as confusing as that of the old-school PC.
"What's different about this holiday season is that consumers have not just more choice, but really good choices," said Sarah Rotman Epps, who studies consumer computing trends at Forrester. "There have been many iPad wannabes but no real quality alternatives, and now there are several."
While choice is a good thing for consumers, she said, it also makes shopping "confusing and complicated."
For the companies that make tablets, the choice means everything. The stakes are much higher than the sale of individual devices. Each company is trying to snag lifelong customers for their other products — like music, apps, e-books, movies, Web search or word-processing software.
While Apple has dominated the market until now, selling more tablets than any other company, its perch is being threatened by the newcomers.
"Apple left a lot of room for rivals to grow," said Tero Kuittinen, an independent mobile analyst.
By keeping its tablet prices so high, he said, Apple could lose its place as the biggest tablet seller, just as it did with smartphones when it lost the first-place position to Samsung, which makes less expensive phones using Google's Android software. The iPad still dominates the market with a 50 percent share, according to third-quarter figures from the research firm IDC, but that is down from 60 percent a year ago. Samsung is in second place with an 18 percent share, Amazon is third with 9 percent, and Asus, which makes Google's Nexus 7 tablet, is in fourth with 8.6 percent of the market.
But Google, which makes the vast majority of its revenue on Web ads, still lags in the tablet market, even though sales of its Nexus 7 tablet are approaching one million a month, according to Asus. About 98 percent of Web traffic from tablets comes from iPads, according to Onswipe, a digital publishing company. Google would like more of that traffic, as well as more buyers for apps and media from its Google Play store, as would Amazon and Microsoft .
"The first decision you make is what ecosystem am I in, do I want the Android Play store and content or some other?" said Hiroshi Lockheimer, Google's vice president for engineering for Android. "So the importance of the ecosystem can't be overstated."
But the decisions after that are still complex.
Say, for example, that you want a tablet that runs Google's Android operating system. There is the Nexus 7, a seven-inch tablet made by Asus, and the Nexus 10, a 10-inch tablet made by Samsung. Then there are the Samsung Galaxy Tab 2 10.1 and the Samsung Galaxy Note 10.1 (not to be confused with the Samsung Galaxy Note 2, a 5.5-inch smartphone). And that's not to mention the dozens of Android tablets made by Lenovo, Toshiba and others.
This year, Microsoft also has a tablet, called Surface. Amazon has the Kindle Fire and Fire HD, and Barnes & Noble has the Nook HD and HD . Once shoppers choose one, they have more choices to make, like whether they want to pay $15 more for the privilege of not seeing ads on the Kindle Fire.
Even Apple, which has always prided itself on having simple product lines, now offers the new iPad, the older iPad 2 and the iPad Mini. If you factor in the various amounts of storage and the choice of cellular data or just Wi-Fi, there are essentially 14 iPad models to choose from.
Complicating the decision on hardware, different tablets connect to different online stores for apps, music and video. If you have built your music and app collection on Apple devices, an Android tablet may mean starting from scratch, and vice versa.
The proliferation of products is nothing new for a mature market, as anyone who has stood in front of a wall of televisions at Best Buy or in a parking lot of Priuses at a Toyota dealership knows.
But some consumer electronics companies that have given their customers too many options have run into trouble, said Shaw Wu, an analyst at Sterne Agee. They include Motorola Mobility, which is trying to rescue its cellphone business by paring its lineup of 27 devices, and Research in Motion, which offers a perplexing matrix of BlackBerrys with confusing names, like the BlackBerry Torch 9810, 9850 and 9860.
Google in particular runs this risk, said Michael Gartenberg, a technology analyst at Gartner, because it gives away its Android operating system to any device manufacturer that wants to use it, resulting in an uncontrolled array of Android devices running different versions of the software. Some apps will work only with particular versions, making it difficult to know exactly what you are getting.
Google has tried to address this problem in recent months. It gave its line of Nexus products names corresponding to their screen size and began selling them in its Play store. (Google teams up with manufacturers to build the Nexus devices.) It began running ads for the tablets online, on billboards, in print and on television, which had been rare for the company, and assigned a public relations employee to focus on selling hardware to consumers.
"I don't think the added choice is adding complexity," said Mr. Lockheimer of Google. "If you want to do the research, you can do it, but if you don't want to, you can just ignore all that and get the thing your friend or family member recommended."
For shoppers inclined to do the research, many Web sites and apps, including those from CNet, Retrevo, Decide.com and Consumer Reports, can help.
"Even those of us who eat and breathe tech, we're still confused," said Lawrence Fong, co-founder of BuyVia, a shopping app that compares products, including tablets. "That's why we're explaining each product in plain English."
The default choice for shoppers, Ms. Rotman Epps said, is often an iPad. "It is a road-tested product, it comes with the Apple quality halo around Apple's brand, and it's leagues ahead in terms of the apps available for it," she said.
But iPads are more expensive than other tablets. They range from $330 for the least expensive iPad Mini to $830 for a 64-gigabyte iPad with cellular data and Wi-Fi.
Google and Amazon advertise their tablets as offering the best value. The Nexus 7 starts at $200 and the Kindle Fire starts around $160.
Microsoft says the Surface, which starts at $500, is better for getting work done, because you can hook up a mouse, type more easily with an add-on keyboard and cover, and use some Office applications.
But the bold design of Microsoft's new tablet software and hardware could be too confusing for Windows users, who tend to be less tech-savvy, Ms. Rotman Epps said. "Given the profile of who wants to buy a Windows tablet, complexity is not a good thing," she said.
For many people, the biggest factor to consider when choosing a tablet is where it takes them once they turn it on — that is, which services, apps and stores selling books and music they can use.
"We've been in love with the glass," said Mark Curtis, chief client officer at Fjord, a mobile design firm. "Now we're going to fall in love with what's behind the glass. It's about the services they can offer."
And, as often happens when a market matures and becomes saturated, companies are beginning to look beyond tablets to the next generation of devices, which might be worn on people's bodies or installed in their homes, Mr. Curtis said.
If you think this year's holiday shopping list is complicated, wait until next year, when it might include Internet-connected watches, eyeglasses or coffee pots.