When HTC announced that its One M9 would be available for pre-order starting tonight at midnight, Samsung stepped up to the plate to offer pre-orders on its Galaxy S6 and Galaxy S6 Edge on the same day. But now the question is which one you'll be pre-ordering for yourself. Luckily, we've devoted this entire article to comparing the S6 with the M9, so you can make a more informed choice at the stroke of midnight.

Both devices were unveiled at the Mobile World Congress earlier this year and both will be available on April 10, so tonight's simultaneous pre-order madness means we're really down to the wire.

Specs

The Galaxy S6 features Samsung's own Exynos 7420 CPU with 3 GB of DDR4 RAM and either 32, 64, or 128 GB of storage. The 5.1-inch screen runs at 1440 x 2560 Quad HD resolution and an impressive 577 pixels per inch. 

The S6 and the S6 Edge are identical in most specs, but the Edge features a slightly larger battery (2,600 mAh vs. 2,550 mAh in the S6) and a slightly lighter case (4.7 oz vs. 4.9 oz in the S6). 

The S6 also features a 16-megapixel rear camera with optical image stabilization and a 5-megapixel front camera that is capable of 1080p resolution at 30 frames-per-second.

As for the One M9, we see some markedly similar specs. The 5-inch display is capable of 1920 x 1080 resolution but only at 441 pixels per inch. The Qualcomm Snapdragon 810 is 2015's high-end processor that's featured in most top smartphones, but Samsung opted to ditch it after some overheating issues during testing. The 810 isn't expected to have those same problems in the M9, though.

Other similar specs include the same 3 GB of DDR4 RAM and a storage capacity of 32 GB standard, although the M9 is capable of expansion up to 2 TB through microSD removable storage. That certainly puts a plus on the side of the M9.

The M9 also has a beefier battery at 2.840 mAh and an impressive 20-megapixel rear camera, although the optical image stabilization of the S6 isn't there.

Price

Off-contract, the One M9 will fetch $649 for the 32 GB base model through both HTC and T-Mobile, while AT&T's off-contract price is a bit higher at $708. On-contract, though, AT&T is offering the M9 for $199.

Sprint and Verizon are expected to announce their pricing structures today.

For the Samsung products, T-Mobile's price starts at $679 on the S6 32 GB model and goes up to $959 for the 128 GB S6 Edge model. Sprint is offering the S6 at $650 off-contract with contract pricing starting at $80 a month to $95 a month for the top-of-the-line 128 GB Edge version.

AT&T says that the 32 GB model will cost $200 on-contract while the Edge will be $299. Without a contract, those prices go to $685 and $814 respectively.

U.S. Cellular has similar pricing with a contracted S6 starting at $199, and $299 for the Edge version.

Verizon hasn't revealed their pricing structure yet, but is expected to today.