Comcast (News - Alert), an Internet and cable service provider, announced it is doubling the speeds of two of its popular XFINITY Internet speed plans in California for no additional cost.

The new speeds are applicable to Blast! and Extreme 50, which allow customers to enjoy faster Internet speeds on multiple devices.

For the Blast! Plan, Comcast has increased download speeds from up to 25 Mbps to up to 50 Mbps; and upload speeds from up to four Mbps to up to 10 Mbps. Extreme 50 customers will receive download speeds up to 105 Mbps (formerly 50 Mbps) and upload speeds up to 20 Mbps (formerly 15 Mbps).

The company also increased the speed of its Performance plan -- up to (20 or 25) Mbps from 15 Mbps downstream and to (4 or 5) Mbps from 2 Mbps upstream.

The new speeds will be available to Santa Cruz/Scotts Valley Area customers this summer. Meanwhile the company said customers in Arbuckle, Maxwell, Williams, Auburn Lake Trails, Isleton, Tower Park and Rio Vista will not receive the new speeds.

Blast! customers who have a 1.1 or 2.0 cable modem will need to exchange their modem for a 3.0 device to achieve the new speeds. 

To activate the new speeds, customers just need to re-start their cable modems.

The development is part of Comcast strategy to address the evolving needs of customers who use multiple devices such as smartphones, laptops and tablets. They can surf, chat, stream HD movies or play game online with double the original speed.

"As customer demands and technology evolve, we continue to increase our broadband speeds to deliver the best, fastest and most reliable Internet experience possible for our customers," said Hank Fore, regional senior vice president for Comcast California, in a statement. 

"Whether chatting, surfing, streaming, gaming, skyping or downloading, families will get the superfast, high-performing Internet service they need, with no extra charge," Fore added.

Comcast is not only delivering the nation's fastest Internet, but it is also providing the fastest in-home Wi-Fi with its latest Xfinity Wireless Gateway (News - Alert), the company said. The Xfinity Wireless Gateway delivers faster speeds with the most coverage in home so everyone can get online and do more on their devices all at the same time.