SAN FRANCISCO — Google will sell a small tablet computer bearing its brand in a challenge to Amazon’s Kindle Fire.

The Nexus 7 is designed for Google Play, the online store that sells movies, music, books, apps and other content — the things Amazon.com Inc. also sells for its tablet computer.

Both tablets have screens that measure 7 inches diagonally. Apple’s popular iPad measure nearly 10 inches. The Nexus 7 will also be light — at about 0.75 pound, compared with the Kindle Fire’s 0.9 pound. The iPad weighs 1.44 pounds.

The Nexus 7 will ship in mid-July starting at $199 — the same as the Fire. By contrast, iPads start at $499.

Andrew Rassweiler, an analyst with IHS iSuppli, said he suspects Google will be subsidizing the tablet to sell it starting at $199. The Kindle is believed to be roughly break even at that price. Samsung Electronics Co. sells a tablet similar to Google’s for $250.

The Nexus 7 has more features than the Kindle, including a front-facing camera. The Nexus 7 will run the next version of Google Inc.’s Android operating system, called Jelly Bean.

Google also announced a home entertainment device called Nexus Q. It sends content from your personal collection or YouTube to your existing TV and speaker systems. You control it through a separate Android phone or tablet.

The Nexus Q, which Google is calling the world’s first “social streaming device,” will available in July and sell for $299.

Google made the announcements during a keynote to open its annual conference in San Francisco for computer programmers.

Google’s expansion into the tablet market with the Nexus 7 brings another imposing entrant into what is already a battle of tech heavyweights. Last week, Microsoft Corp. announced its own tablet, Surface. Expected to go on sale this fall, Surface will run on a revamped version of Windows and compete directly with the iPad.

Although the tablet carries the Google brand, the machine will be made by AsusTek Computer Inc. Google also recently expanded into the device-making business with its $12.5 billion purchase of Motorola Mobility, but the company has stressed that it intends to continue to rely on Asus and other manufacturers that have embraced Android.