Samsung Electronics and Toshiba have both unveiled tablets computers at the IFA electronics show in Berlin to rival Apple's iPad.
Both companies claim they can also compete with Apple on content, services and a greater range of devices, according to the Financial Times.
Samsung's Galaxy Tab weighs in at just 380g, has a seven-inch screen and runs the latest version of Google's open-source Android operating system.
Pricing details have yet to be announced for its October release in the UK, but Samsung said it is negotiating with mobile carriers around the world to sell it like a subsidised mobile phone.
Toshiba's Folio 100 also runs Android, which means both can play Flash movies, unlike the iPad, but weighs double the Galaxy Tab at 760g with a 10.1-inch screen.
The company plans to sell directly to consumers, but a 3G option means carriers may also offer the device, which is expected to retail in the UK for £329, also from October.
In contrast, the iPad runs Apple's proprietary operating system iOS, weighs 730g with a 9.7-inch screen, and retails for between £529 and £700.
Sony has also used the IFA show in Berlin to challenge Apple's dominance in the digital media market by announcing its new Qriocity video and music service.