Google has unveiled its latest flagship Android phones at a special media event in San Francisco. The Nexus 5X (made by LG) and the Nexus 6P (made by Huawei) carry the brand new Android Marshmallow OS and are intended to take on the iPhone 6S and iPhone 6S Plus recently launched by Apple.

The Nexus 5X is the smaller, cheaper and less powerful of the two handsets: with a 5.2 inch display running at a 1920 x 1080 resolution (424 ppi), the phone packs a 64-bit Snapdragon 808 CPU with 2 GB of RAM and either 16 GB or 32 GB of internal storage. A 12.3 MP rear camera and 5 MP front camera round off the major features.

Those are decent but not ground-breaking specifications, and at a starting price of US$379 (international pricing to be confirmed) this is obviously Google's push at the mid-to-top range. The phone offers 4K video recording and a fingerprint scanner, and is the follow-up to the 2013 Nexus 5 (also manufactured by LG).

The phone is available in three colors called Carbon, Quartz and Ice and comes with a respectably large 2,700 mAh battery. At 147.0 x 72.6 x 7.9 mm it's slightly larger but a touch thinner than the Nexus 5 it replaces.

The Nexus 6P takes over from last year's Nexus 6 (made by Motorola) and features a 5.7 inch 2,560 x 1,440 pixel display (515 ppi) – the same specs as Samsung's Note 5 and Galaxy S6 edge+. Inside there's a Snapdragon 810 processor and 32 GB, 64 GB or 128 GB of internal storage. Like the Nexus 5X the rear camera is rated at 12.3 MP, and there's a 5 MP snapper at the front. The phone is just 7.3 mm thick.

It's not just the Nexus 6P specs that are premium either: the Huawei-made phone is the first all-metal Nexus flagship handset and uses a bright AMOLED panel for its display. Like the Nexus 5X, there's 4K video recording available and a fingerprint sensor, and both handsets feature the new USB Type-C data port. The entry price for the Nexus 6P is set at $499.

Google is making much of the fact that it's about the same chassis size as the iPhone 6S Plus but with a bigger screen (5.5 inch vs 5.7 inch); it's also lighter (178 g vs 192 g). Three colors are available: Aluminum, Graphite and Frost.

Google was keen to push the advanced sensor inside the new Nexus devices, claiming it's notably better than Apple's latest handsets at capturing details in low light. It does slow motion too: 120 frames-per-second on the Nexus 5X and 240 fps on the Nexus 6P.

On the downside, the two phones lack microSD card expansion slots (like the LG G4 has), wireless charging capabilities (like the Samsung Galaxy S6 has) and optical image stabilization technology (like the iPhone 6s Plus has). On stage in San Francisco, Google's Dave Burke said the new Sony sensor was so good, OIS wasn't necessary.

We'll have to wait until we get our hands on the new Nexus devices to see if they're ready to challenge the Apple iPhone, but on paper at least they have a chance – and with Android Marshmallow on board they represent the very best that Google's software engineers can offer. After the supply problems suffered by the Nexus 6 and the Nexus 7 tablet disappearing from sale, it's been a tough couple of years for the flagship Nexus program: time will tell if these new smartphones can make up the lost ground.

If you want to check for yourself, the phones are available to preorder in the U.S., the U.K., Ireland and Japan, with shipping scheduled for the end of October.

View gallery - 14 images