Razer Viper V4 Pro Review

The Razer Viper V4 Pro is the latest entry in Razer's Viper line of competitive gaming mice, and it arrives with a clear brief: take the well-liked Viper V3 Pro and sharpen every edge. Independent laboratory testing rates it an outstanding FPS gaming mouse — a featherweight, ultra-responsive tool aimed squarely at players competing at the highest level.

The Viper V4 Pro keeps the low-profile symmetrical shape that made its predecessor a staple, but shaves a little more weight to reach roughly 49 grams. The test praised the build quality as excellent and the mouse as extremely lightweight and well-balanced, which makes it easy to flick quickly and stop accurately. That accommodating symmetrical shell suits a wide range of hand sizes and grip types, from claw to fingertip, and there is a choice of black and white colourways with only very minor differences in weight and coating feel between them.

Players with larger hands who prefer a palm grip may still find a shaped, right-handed design more comfortable — the test points to the Razer DeathAdder V4 Pro as the alternative there, with similar performance in a bigger body.

This is where the Viper V4 Pro earns its recommendation. The test measured exceptional raw performance, with incredibly low click latency and sensor latency — the kind of responsiveness suited to the most demanding competitive play. A new sensor delivers iterative improvements to motion tracking over the V3 Pro, and the mouse ships with a redesigned dome-shaped wireless receiver featuring a taller embedded antenna for a more reliable connection. Razer has also switched to an optical scroll-wheel encoder in place of a mechanical one, which should improve long-term scroll durability, and advertised battery life is longer than before.

Customisation runs through Razer's software, available as a downloadable desktop application or a web-based client, covering button remapping, sensitivity stages, lighting and calibration. The one clear drawback the test flagged is noise: the main clicks are loud, which may bother anyone gaming in a shared space or streaming with an open microphone. It is a minor complaint against an otherwise polished package, but worth noting if a quiet setup matters to you.

The Viper V4 Pro's most direct rival is the Logitech G PRO X2 SUPERSTRIKE, which introduces adjustable click actuation and haptic feedback; by comparison, the Viper focuses on refined, iterative gains rather than headline new technology, and it remains lighter. Both sit at the top of our best wireless mice guide, where the Viper V4 Pro is the pick for lightweight FPS play. Those who want more programmable buttons for MMOs or a broader mix of genres should weigh the Razer Naga V2 Pro or the Logitech G502 X PLUS instead, while shooter purists cross-shopping the featherweights should also read our Logitech G Pro X Superlight 2 review.

The Razer Viper V4 Pro is a superb competitive gaming mouse that does exactly what it sets out to do: trim weight, tighten latency and shore up the details that matter over years of use. Its featherweight balance, accommodating symmetrical shape and elite responsiveness make it an easy recommendation for FPS players, and only its loud clicks give any pause. For anyone chasing the lowest weight and latency in a wireless mouse, it belongs at the top of the shortlist — pair it with a capable rig from our best gaming PCs guide and a fast display to feel the benefit.

This review is based on independent laboratory testing rather than our own hands-on trial.