Razer Basilisk V4 Pro: New AI Button Complicates Thumb Ergonomics

Razer has released the Basilisk V4 Pro, a gaming mouse that attempts to balance advanced features with ergonomic comfort. The core conflict of the device lies in its new layout. While the mouse offers a 200-hour battery life and a lighter frame, the addition of a dedicated AI key has altered the placement of thumb controls, creating reach issues for some users.

The V4 Pro launches at $169.99 in black and white. It connects via 2.4GHz wireless, Bluetooth, or USB-C. The device features Razer's Focus Pro 50K optical sensor, which supports polling rates up to 8,000 Hz. It includes fourth-generation optical switches rated for more than 100 million clicks. Sarah Jacobsson Purewal, senior editor at Tom's Hardware, tested the unit and found the switches produced no misclicks or double-clicks during her evaluation.

The primary design change involves the button cluster. The V4 Pro now has 12 programmable buttons, up from the previous model. A new third thumb button sits in front of the existing two and triggers an AI prompt by default. A separate button located beside the left click key switches profiles. Purewal found the profile button too far forward for comfortable use with medium-sized hands. The AI button, being the same size as its neighbors, pushes the other thumb keys backward. This shift makes the first thumb button difficult to reach, a layout issue that persists even if users remap the keys.

The mouse weighs 100 grams, a reduction of 12 grams from the 112-gram V3 Pro 35K released in October 2024. While still heavier than ultralight competitors, the reviewer noted the device is easier to pick up. The tilt wheel offers 24 or 48 tactile steps and a free-spin mode. The free-spin setting proved too sensitive and prone to unintended scrolling, while the precision tactile mode received positive feedback. The device measures 127.5 millimeters in length.

Battery performance has increased from 150 hours to 200 hours at a 1,000 Hz polling rate over 2.4GHz. At the maximum 8,000 Hz polling rate, the battery lasts 54 hours. The launch includes the Mouse Dock V2 Pro, sold separately for $69.99. The dock features an integrated 8,000 Hz receiver and eight RGB zones. The package includes a USB-A dongle, an adapter, and a six-foot braided cable, but it does not include grip tape or a flexible HyperFlex cable.

Tom's Hardware positions the Basilisk V4 Pro between the DeathAdder V4 Pro and the Naga V3 Pro. The review cites the comfortable feel, reduced weight, and extended battery life as strengths. The drawbacks include the price, the slightly large size, and the ergonomic impact of the AI button on the thumb cluster. The mouse is recommended for players who want more functionality than a basic shooter mouse but do not require a high button count.