When it released in 2020, the Viper Mini was among the finest budget mice available at the time. After having been discontinued, a successor was in order, which improves on the Viper Mini in several ways.

As with the Cobra Pro, the shape of the Cobra doesn't match that of the Viper Mini entirely. The Cobra is a bit longer, and both aesthetic and geometric changes have been made to the front, hump, and scroll wheel, too. In practice, however, the Cobra and Viper Mini feel very similar if not identical. In addition, instead of the rubber side grips of the Cobra Pro, the Cobra retains the plastic sides of the Viper Mini. The weight also is largely unchanged, and I've found the build quality to be on a similar level, too: On my sample, there is no rattle when shaking the mouse, pressing below the side buttons doesn't result in them being actuated, and the shell does not creak or flex when applying lateral force.

While the Viper Mini already was outfitted with optical switches for the main buttons, these have been updated to their latest-generation equivalents on the Cobra. Comparing the two directly, the third-generation switches on the Cobra elicit a sharper, yet also slightly more muted button response, which is why I prefer the Viper Mini main buttons personally. Both buttons have some pre-travel, but post-travel is low, and lateral movement of the buttons is kept to a minimum. For the side buttons, the same switches as on the Viper Mini are used still, but their design has been revised, as instead of being vertically mounted atop the PCB, they now sit flush on the PCB, and are actuated by small stems that are part of the side button pieces. The result is low pre and post-travel on both buttons, along with even actuation across the entirety of these, though the feedback isn't all that pleasing. The scroll wheel encoder is unchanged from the Viper Mini, still being a Kailh black, which provides nice tactility, with clearly separated steps, but elevated noise levels, especially when scrolling down. The feet likewise are unchanged, still made of pure PTFE, and glide very well. Of particular note is the fact that their size and shape hasn't been altered, either, so third-party skates made for the Viper Mini can be used on the Cobra just fine. Nominally, at least, the cable is also the same as on the Viper Mini, though I've found it to be a bit more flexible on the Cobra. While not the most flexible stock cable around, this one is at least flexible enough to not be bothersome during use.

The most notable change pertains to the sensor. Now dubbed PAW3349, the sensor still is 8-pin, but the lens and illumination are new, resulting in a very noticeable improvement to lift-off distance. Whereas on the Viper Mini, getting lift-off distance below 1 DVD was difficult to impossible without tracking being adversely affected in the process, the Cobra manages a lift-off distance of below 1 DVD out of the box. Adjustment is still only possible by utilizing Razer pad presets, but considering that most people prefer a lift-off distance of below 1 DVD, the default should already suit the vast majority of people. Sensor performance is largely on par with the Viper Mini, though smoothing has been added. On the release firmware of the Viper Mini, there was no smoothing across the entire CPI range, resulting in motion delay being the same regardless of the set CPI step, whereas on the DeathAdder V2 Mini (same sensor) and latest firmware of the Viper Mini, smoothing is first introduced at 3300 CPI. On the Cobra, smoothing is present as well, though I'm unable to confirm whether it is actually introduced at 3300 CPI. Polling is stable throughout, and there are no issues related to general tracking. CPI deviation continues to be less than ideal, and, if anything, worse than on the Viper Mini. There is significant positive deviation of varying degrees, though on the plus side, this can be adjusted for quite easily now, since the 3349 allows for CPI adjustment in increments of 50, instead of 100 on the Viper Mini. Lastly, click latency is virtually the same it was on the Viper Mini, clocking in at 0.9 ms.

As with other Razer mice, configuration is done in Synapse. Resource usage continues to be as high as ever, and this applies to the number of processes running the background, too. That said, considering how little there is to adjust on the Cobra to begin with, skipping Synapse entirely is perfectly possible. Those wanting accurate CPI steps will want to run Synapse for adjustment at least once, however.

The fact that the Cobra is priced at the same $39.99 as the Viper Mini says more about where the market is headed than anything. Back in 2020, the Viper Mini didn't enjoy a lot of competition simply by virtue of being ahead of the curve. These days, the market has shifted towards wireless, which is why the Cobra mostly receives pressure from budget wireless mice, which often break into the $50 or under price bracket, especially those from Chinese brands. Hence, when compared to these, the Cobra doesn't compare too favorably, but in relation to its own peers, the Cobra looks far better. The Cooler Master MM310 is priced at $29.99, even lighter at 53 g, but doesn't have optical main button switches, has a higher lift-off distance, and can't compete in terms of performance. The older ROCCAT Burst Core does have optical switches and performs well, but does weigh a decent bit more while being larger, has a higher lift-off distance, and, most importantly, has a significantly stiffer cable. And that is already pretty much it as far as as direct competition goes. Accordingly, the Cobra earns our Budget and Recommended awards.