Mind-blowing battery life; excellent wireless performance; fantastic price


No RGB lighting; heavy when using two AA batteries; no side grips

Star Rating



Here at TBG, we love testing new mice, and we're always happy to see recent innovation in a market that was dormant for far too long. While we've tested plenty of cool mice over the past few years, some of our very favorite mice over the past few years have come from Logitech, including its G602 Wireless Gaming Mouse, the G502 Proteus Spectrum Wired Mouse, which won our big gaming peripherals shootout, and most recently its G403 Prodigy Wireless Gaming Mouse. We crowned that last mouse the best mouse we'd ever tested, and in fact it's the mouse we've chosen to use ever since, despite other models passing through our hands. What's particularly interesting about Logitech is that it appears to have moved far beyond its competitors in one important feature: wireless connectivity. While most of its competitors don't even offer wireless gaming mice, Logitech has clearly embraced the technology, moving all of its high-end mice to wireless. The wired G502, released several years ago and currently the best-selling gaming mouse in the world, is now heavily discounted and likely will not be replaced. And as we found in our review of the G403 Prodigy upon its release in 2016, Logitech has clearly made great strides in making wireless mice just as responsive as wired mice, if not more so. There was just one challenge that remained in terms of making wired mice entirely obsolete: battery life.

Well, for 2017, Logitech is addressing this last barrier to adoption in several innovative ways. First, Logitech has actually replaced the G403 after just one year with the new G703 Lightspeed, which is the same mouse, but with wireless charging added as an option. In other words, the user will never need to stop to charge its batteries. But this amazing system doesn't come cheap; the total price of the G703 plus the as-yet-unreleased wireless charging mousepad will be $200. Luckily, Logitech's engineers have another way of attacking the problem: making the mouse more efficient. In this review, we'll be testing its latest entry in the efficiency wars: the new Logitech G603 Lightspeed Wireless Gaming Mouse. Coming in at a very reasonable $70, it's based on the G403, which debuted at $100 last year, but has been redesigned internally for use with AA batteries just like the aging G602, while offering far better battery life than either model. Note that the G602 was once Logitech's high-end wireless gaming option, but it's currently selling for $35 and is our top pick for a mid-range office mouse. We expect it to be discontinued sooner rather than later, because it's a steal at that price!

This is all to say that Logitech isn't sitting still in the wireless mouse market, despite the lack of competition. In fact, it's working hard to establish itself as the only manufacturer to consider for wireless mice, and it's not afraid to put relatively-new models out to pasture to clear the decks for its very best offerings. So, if the G403 was our favorite high-end mouse ever, and the G602 was our favorite mid-priced wireless mouse, is the G603 really the best of both worlds, and thus the best mouse to ever slide across a mousemat? Read on to find out!

We'd like to extend a special thank you to Logitech for providing us with a review sample of the Logitech G603 Lightspeed Wireless Gaming Mouse.


Description and Features

Shown above on the right, the G603 is clearly derivative of the G403, shown on the left. The G603 offers the subtlest of aesthetic changes, including the switch to a slate-grey top for a little extra style and the removal of the G403's RBG lighting. Yes, you read that right, the G603 has no RGB lighting, making it likely the only gaming mouse on the planet over $30 that has no lighting whatsoever. If that rubs you the wrong way, there's little we can do to make things right. Might you take consolation in the fact that the RGB lighting on the G403 was clearly tacked on, and didn't even work right until 8 months after release? Yeah, Logitech really doesn't get RGB lighting, and the fact that it cut the battery life on the G403 down from 32 hours to 20 hours didn't make things any better. We're glad Logitech has moved on from trying to fight a battle it was bound to lose, and has instead focused on what it does best: making world-beating mice.


OK, let's get into some of the features that the G603 actually does offer, shall we? Logitech is making a big deal of its new home-grown High Efficiency Rated Optical (HERO) sensor, claiming that it's 10x more efficient than the excellent PixArt PMW3366 optical sensor in the G403, with no degradation in performance. It's still capable of 12,000dpi, and presumably has the same stellar latency ratings, which we'll be putting that to the test on the next page. The G603 loses the rechargeable lithium battery of the G403, and instead relies on two AA batteries, as in the G602. And just like that mouse, it can run on just one battery, which is a huge advantage for gamers, due to the weight of AA batteries. On our scale, the G403 weighs 105g (or 115g with its optional weight module), the G602 weighed a portly 154g with two AAs and 131g with one, and the new G603 weighs 135g with two AAs and 112g with one. In other words, it's nearly as trim as the G403, and even with one AA, it blows away the G403 in terms of battery life.


Let's discuss that issue in more detail, because it's a really big deal, and it's what makes the G603 so unique. The G603 has three modes: high-performance mode, low-performance mode, and Bluetooth mode. The latter two behave the same way, running a total of 1,400 hours on two AAs (or 700 hours on one), by virtue of a rather leisurely 8ms polling rate (125 reports per second). In high-performance mode, the G603 utilizes a 1ms polling rate (or 1000 reports per second), and can last 500 hours with two AAs, or 250 hours with one. Give that a moment to sink in. Even with a single AA battery, this mouse lasts 8x longer than the G403 even when that mouse had its RGB lights shut off. And it weighs just 7g more. And it costs $30 less. That's some serious wow, folks!

While it doesn't have nearly as many buttons as some of its stablemates, at least the G603 has the ones that really count: a DPI selector switch up top, a solid-feeling scroll wheel with a grippy rubber texture, and two big thumb buttons on the side. Whether you like the size of these depends on how much effort you want it to take to hit them. Yes, we did just lose multiple paragraphs of this review by accidentally hitting the "back" button, but that's our fault, right? We still prefer this approach to the slimline buttons that most competitors are using, which take a lot more effort to hit while in-game. As you can see in our semi-exploded view to the left, the top two switches really are Omron models, which are the best in the business (apparently, Logitech hasn't yet decided to reinvent the switch like it has the sensor). Take note that the buttons themselves are actually simply extensions of the shell, rather that separate hinged parts as on the G403. We'll discuss the effect of this more on the next page, but in short, it does make them a bit less responsive.


Logitech's excellent Logitech Gaming Software (LGS) of course plays a role in the whole G603 experience, but given the relatively few buttons and complete lack of lighting, it's a lot less significant that it would be with other peripherals. It doesn't even provide estimated battery life, which we really miss from the G403 and many of Logitech's other peripherals, but we'd guess that there's just a bit too much margin of error when you're talking about the potential for 1400+ hours of battery life. Instead, the software simply displays which mode you're in (the green emblem in the upper-left of this screenshot indicates low-power mode, or what Logitech calls "endurance"). When in performance mode, that emblem is blue.

Let's move onto our subjective performance evaluation, and then finish up with our overall thoughts.

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