There’s a gentle scoop-shaped slope on the left side and a resting spot for your thumb (this is definitely a right-handed mouse) that doubles as an extra, configurable button, though I wish this “hidden button” under the thumb rest was easier to press as I needed to unnaturally reach back to hit it, because the pressable part is at the base of the thumb. On the MX Master 3, which has been my daily driver for months, this button was extremely stiff but on the MX Master 3S, it’s much softer though still in the same, less-than-convenient place.

The forward / back buttons and horizontal scroll wheel are conveniently-placed right above the thumb rest area, along with an LED charge-indicator light that only lights up when you’re charging the mouse or it’s low on battery. On top of the mouse are the scroll wheel, right and left click buttons and a small button below the scroll wheel that’s configurable but defaults to changing the scroll wheel’s mode.

Using magnets to adjust the amount of friction, the “MagSpeed” wheel can toggle between FreeSpin and Ratchet mode scrolling. So, if you want to scroll really quickly, the wheel can loosen up and offer very little resistance, allowing you to go past 1,000 lines per second. But, if you need precision, it will switch back to providing tactile bumps as you move. By default, the Logitech Options+ software uses a feature called SmartShift to switch the modes back and forth based on how fast you are spinning the wheel. In practice, I found SmartShift, which you can adjust the sensitivity of in software, more than adequate so I never needed to use the manual toggle button.

The bottom of the Logitech MX Master 3S is identical to the prior model, with three smooth black strips to help the device glide around, a power switch, the Darkfield sensor and the device-switching button. We’ll cover this more below when we talk about connectivity. But having to turn the mouse over in order to switch from one connection to another is really lame, although if you’re primarily using the mouse with one computer at a time, this probably won’t matter to you.

For charging, there’s a USB-C port on the front of the mouse, in a recessed space. You can’t strictly use the mouse via a wired USB connection, but it can charge while connected wirelessly and I found that having it plugged in did not make it any more difficult to move the mouse around.

New and Polarizing Buttons on the Logitech MX Master 3S

In the most radical change from prior MX Master mice, the MX Master 3S’ left and right click buttons use new, quiet switches that Logitech says offer 90 percent noise reduction over the prior model. The switches are indeed significantly quieter than those of most mice, but they also have a completely different feel which can seem mushier and less tactile.

I also showed the MX Master 3S’s buttons to a few other people, none of whom spent much time with it. My coworker, Andrew, who likes quieter keyboard switches appreciated the lighter feel. However, my wife and son really disliked it.

Whatever you think about the feel of the mouse buttons, they definitely deliver on their promise of being quieter. I rapid-clicked the MX Master 3S and the MX Master 3 on a Google Meet call with my coworkers and they could clearly hear the 3 but barely made out the 3S. However, neither mouse was audible when I turned on Google Meet’s noise-canceling feature, which is enabled by default. Given that Zoom has a similar feature, it’s not clear that having a quieter mouse matters for conference calls. However, if you’re in an in-person meeting or working in close-quarters with others, the lower noise level could be helpful.

Productivity Performance of Logitech MX Master 3S

The Logitech MX Master 3S is a joy to work with. The combination of its comfy grip, electromagnetic scroll wheel, thumb wheel and fantastic sensor makes it easy to get more done. The Darkfield sensor works smoothly on just about any surface, even glass. When I placed it on top of a glass tablet screen, navigation was just as accurate as it was on a mousepad.

The sensor can go from 200 all the way up to 8,000 DPI, double the 4,000 DPI of the MX Master 3. However, the mouse defaults to 1,000 DPI (as it did on the MX Master 3) so you have to go into the Logi Options+ app and change it before you’ll actually see a difference.

Logitech told me that the purpose of doubling the sensor DPI is to help users who have multiple monitors move their pointers around all that screen real estate without pushing the mouse too far and overworking your wrists. I’m the ideal audience for this feature, because I use a four-monitor setup at home and, indeed, turning up the DPI in Logi Options+ made it easier for me to navigate around my desktops, but I’m not sure that I need much more than 4,000 DPI. Turning my DPI up all the way to 8,000 or close to it made the pointer too fast for me to avoid overshooting my targets. However, 5,000 DPI seemed like a sweet spot on my four-monitor setup.

The MagSpeed scroll wheel was a huge convenience to me editing long documents, vertically navigating large spreadsheets or reading web pages. I found the SmartShift feature more than adequate for switching between FreeSpin and Ratchet modes automatically so I didn’t need to manually toggle using the shift wheel mode button.

I found the thumbwheel particularly useful because it allowed me to zoom in and out on web pages, documents or PHP and JavaScript files I was editing in Notepad++. In addition to using it for zooming, you can configure the wheel for horizontal scrolling, volume control, navigating among tabs, forward/back or a keyboard shortcut.

Connectivity and Logitech Flow on MX Master 3S

Like its predecessors, the Logitech MX Master 3S can connect to up to three devices wirelessly and quickly switch among them using either the Easy-Switch button on its bottom or the Logi Flow feature of the Logi Options+ app. You can connect via either Bluetooth or a Logi Bolt dongle. One Logi Bolt( dongle that’s already pre-paired with your mouse comes in the box, but you can also use a dongle that you got elsewhere if you pair with it using Options+. You don’t need the software to do Bluetooth pairing, which is important because only Windows and macOS can run the app.

Note that the MX Master 3S is not backward compatible with Logitech’s Unifying Receiver, which was the dongle standard before Bolt and the one used with the MX Master 3. The Logi Bolt is also not backward compatible with devices that work with the Unifying Receiver. The company has been switching to Bolt from Unifying Receiver because Bolt offers better security and less latency, particularly in environments with lots of wireless devices. But if you’re invested in multiple Logitech devices and don’t want to use multiple USB ports for those devices, the transition is still a pain

Because I have four monitors on my desktop, stacked in a 2×2 layout, I sometimes accidentally ended up dragging my pointer onto the laptop when I was just trying to move between the top right and bottom right monitors as going off the right side of the top monitor or the bottom monitor both took me to the laptop. I strongly recommend enabling the “Hold CTRL and Move Cursor to Edge” setting, which won’t switch devices unless you’re also holding down the CTRL key.

Perhaps most importantly, I was able to take the contents of the clipboard with me when I switched between my two PCs, copying text or an image on the laptop and then pasting it into any app I wanted to on the desktop. This is particularly useful if I want to grab screenshots from Windows 11 and then edit them on my Windows 10 computer.

If you want to switch to a device that can’t run Logi Options+, you can’t use Flow and must rely on the Easy-Switch button. I use a Raspberry Pi with Linux as part of my workflow, so I found it really frustrating that the tiny Easy-Switch button is on the bottom of the mouse where it’s hard to reach. Other Logitech Mice, such as the Triathlon M720, solve this problem by putting that button on top, but the MX Master line hasn’t gotten the memo that some users need easier manual switching. It would be nice if you could custom configure one of the other buttons, perhaps the Shift wheel button or thumb button, to serve as Easy-Switch. But at least right now, you cannot. It would also be nice if switching devices manually on your MX Mechanical keyboard would switch the mouse to the same device, but that’s not an option either.

Software and Customization of Logitech MX Master 3S

You can use the Logitech MX Master 3S without any software at all and it will operate at default settings for the buttons, wheels and DPI. However, to get the most out of it or to use Flow, you need to install Logi Options+, which is the new name for Logitech’s Options software. Available for Windows or macOS, Options+ allows you to customize each button and both scroll wheels by app, control the MagSpeed wheel’s DPI and modes, set up Flow and see a list of all the devices your mouse is paired with. The software also backs up your settings to the cloud, should you need to reinstall the software or start fresh on a new computer.

I found that customizing the buttons provided a really good way to maximize my productivity, but you need to make sure you have the settings tweaked for the apps you use most. By default, the thumb wheel enables horizontal scrolling in Windows but tab switching in Chrome. But I wanted to make sure that it zooms in Chrome and horizontal scrolls in Excel and was able to do so.

Though Options+ includes default settings for a number of apps, including Word, Powerpoint, Chrome, Edge, Zoom and Teams, you can add any application you want as I found when I created custom settings for Notepad++, my favorite code editor. When I wanted to program the shift wheel button to switch tabs in the program, a function that normally requires hitting CTRL + PgUp, I simply selected Keyboard Shortcut as the output for that button in Notepad++.

As powerful as Logi Options+ is, there’s still plenty of room for improvement. As noted above, you can’t program any of the buttons to switch devices – you can only use the bottom button for that. I also couldn’t find a way to set any of my buttons to mute my microphone in Windows, though there is an option to make it mute your speakers. Since so many of the tools I use are web-based, I’d really love to be able to customize the buttons by website, rather than having the same controls for anything I do in Chrome or Edge. For example, it would be more helpful if I could program the horizontal scroll wheel to be zoom in Google Docs but horizontal scroll in Google Sheets and volume control in Google Meet.

Battery Life of Logitech MX Master 3S

Logitech rates the Logitech MX Master 3S for up to 70 days of battery life, just like the MX Master 3. There wasn’t time to put this claim to the test, but after about a week of wireless use, Logi Options+ reported that the battery was still at 95 percent of capacity. The MX Master 3, which has been my daily driver for several months, seems to need a fresh charge every 6 weeks or so.

Bottom Line

Whether you’re a developer, a creative professional, an office worker or a student, having a better mouse can help you get more done in less time. At $99, the Logitech MX Master 3S is expensive, but appropriately priced for a top-of-the-line productivity mouse as it matches the MSRP of both its predecessor and its main competitors: the Microsoft Precision Mouse and the Razer Pro Click, neither of which have thumb wheels or Logi Flow. And, while you can get a decent wireless mouse for far less, the MX Master 3S can change the way you work, especially if you use multiple devices.