The Cooler Master MM731 is an extremely lightweight wireless gaming mouse with a solid plastic shell, two side buttons on the left, and a single RGB lighting zone in the logo on the palm area. It has a comfortable, right-handed shape suitable for all but small-sized hands using a claw grip, medium and large-sized hands using a palm grip, and large or extra-large hands using a fingertip grip. It feels well-built overall, but it flexes slightly and creaks when you squeeze the body, and there's a faint rattle if you shake the mouse. Also, the scroll wheel feels stiff, and the scroll wheel click takes slightly more force to press than on most gaming mice. Performance-wise, the MM731 has very low click latency, a very low minimum lift-off distance, and you can adjust the CPI by increments of 100 within a very wide range.
Note: Many users online have reported a range of issues with the Cooler Master MM731, including but not limited to difficulty updating firmware, squeaky clicks, double-clicking, slam-clicking, high motion latency, and high click latency. In our time testing, we didn't experience these issues on the unit we tested. Cooler Master has stated that these physical issues are mainly present in earlier batches (specifically batch 1212 and 2123.) The unit we purchased is from batch 2128, which Cooler Master claims has been reworked to address the quality control concerns. They also claim recent firmware updates should fix any sensor issues, including motion delay and slam-clicking, but we'll continue to monitor the situation and update this review as needed. We performed our tests with the Cooler Master MM731 firmware version 2.0.9 and receiver firmware 1.2.8 installed. If you own this mouse and would like to share your experience, we'd love to hear from you in the discussions section.
Our Verdict
The Cooler Master MM731 is very good for office and multimedia use. It feels well-built overall and connects wirelessly with its USB receiver or via Bluetooth. You can also use it wired with its charging cable. It has a comfortable, right-handed shape suitable for all grip types, and you can program all buttons using the customization software. Unfortunately, the scroll wheel lacks L/R tilt buttons and a free-scrolling mode.
- Feels well-built overall.
- Comfortable, right-handed shape suitable for all grip types.
- Connects wirelessly with its USB receiver or Bluetooth.
- All buttons are programmable.
- Scroll wheel lacks L/R tilt buttons and a free-scrolling mode.
- Bulky; may not fit in most laptop cases.
The Cooler Master MM731 is an excellent FPS gaming mouse. It's very lightweight and feels sturdy overall. It has a comfortable, right-handed shape suitable for all grip types, a flexible paracord-like cable, and mouse feet that glide smoothly on mousepads and desks. It also has excellent click latency, a very low minimum lift-off distance, and a very broad CPI range. Unfortunately, you can't adjust the CPI as precisely as you can on some other gaming mice.
- Feels well-built overall.
- Extremely lightweight.
- Low click latency.
- Comfortable, right-handed shape suitable for all grip types.
- Bulky; may not fit in most laptop cases.
- Mouse feet are thin compared to most gaming mice.
- CPI only adjustable by increments of 100.
The Cooler Master MM731 is good for MMO gaming, but it doesn't have nearly as many side buttons as a dedicated MMO gaming mouse, but all the buttons it does have are programmable. It feels well-built overall and has a comfortable, right-handed shape. Performance-wise, it has very low click latency, a very low lift-off distance, and a very broad CPI range. Unfortunately, you can't adjust the CPI as precisely as you can on some other gaming mice.
- Feels well-built overall.
- Low click latency.
- Comfortable, right-handed shape suitable for all grip types.
- All buttons are programmable.
- Not nearly as many side buttons as a dedicated MMO gaming mouse.
- Bulky; may not fit in most laptop cases.
- Mouse feet are thin compared to most gaming mice.
- CPI only adjustable by increments of 100.
- Bulky; may not fit in most laptop cases.
Changelog
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Updated Jan 07, 2026:
We've removed outdated text in the Sensor Specifications section, which was mistakenly retained after recent updates and detailed elevated CPI deviation measurements from our older test methodology. We updated the text in the CPI section based on our newer methodology, confirming the mouse doesn't have any significant CPI issues. We've also added updated text to the Sensor Latency section.
- Updated Dec 09, 2022: We've converted this review to Test Bench 1.4. This update modifies our Hand Size Recommendation test, adding a more granular hand size recommendation chart. We've moved several minor tests into different test groups, removed the Travel usage, and added a new Raw Performance usage. For more details, you can see our full changelog here.
- Updated Sep 06, 2022: We've converted this review to Test Bench 1.3. This update adds a new Sensor Latency test and makes minor changes to several of our existing tests, resulting in test result changes in several sections. For more information, you can check out our full changelog here.
- Updated Aug 08, 2022: We've corrected a small error in our Lowest Weight score. We've also added text to the Weight section to clarify the new test results following our methodology update to Test Bench 1.2.
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Differences Between Sizes And Variants
The Cooler Master MM731 we tested is black, but there's also a white color variant available. Also, there's a wired version of the mouse, the Cooler Master MM730. You can see the label for our unit here.
Popular Mouse Comparisons
The Cooler Master MM731 is an exceptional lightweight gaming mouse with a straightforward look and a pronounced right-handed shape. Unlike other mice in Cooler Master's MM710 series, like the Cooler Master MM710 or Cooler Master MM711, this mouse has a solid plastic shell rather than a body with honeycomb cutouts to reduce weight. Despite this, the MM731 is among the lightest mice in Cooler Master's lineup. It also has Bluetooth functionality, which isn't typical for wireless ultra-lightweight mice, and is a helpful feature for conserving battery when not gaming. Additionally, the left and right-click buttons use optical switches, which Cooler Master claims are more responsive and durable than the mechanical switches found in many similar gaming mice.
For more recommendations, see our picks for the best wireless mouse, the best FPS gaming mouse, and the best lightweight mouse.
The ROCCAT Kone Pro Air and the Cooler Master MM731 are both wireless gaming mice with comparable performance. The Cooler Master is lighter and has a higher maximum CPI. It also has one additional programmable button. On the other hand, the ROCCAT feels much better built and has a thumb rest.
The Cooler Master MM731 is a better ultra-lightweight gaming mouse than the Cooler Master MM711. The MM731 has a right-handed shape and connects either wired with its charging cable or wirelessly via Bluetooth or its USB receiver. It's marginally lighter, has a wider CPI range, and has an additional programmable button. It also has lower click latency. On the other hand, the MM711 has an ambidextrous shape and is wired-only. It also has mouse feet that glide more smoothly on mousepads and desks.
The CoolerMaster MM731 is a better ultra-lightweight gaming mouse than the Cooler Master MM710. The MM731 has a right-handed shape and connects either wired with its charging cable or wirelessly via Bluetooth or its USB receiver. It feels somewhat sturdier, has a wider CPI range, and has an additional programmable button. It also has lower click latency. On the other hand, the MM710 is a wired-only model with an ambidextrous shape. It also has mouse feet that glide more smoothly.
The Cooler Master MM731 is an exceptional lightweight wireless gaming mouse, while the GLORIOUS Model D is an excellent lightweight wired gaming mouse. The Cooler Master is lighter and feels sturdier. It also has a much wider CPI range, a lower lift-off distance, and marginally lower click latency. On the other hand, the GLORIOUS has mouse feet that glide more smoothly on mousepads and desks. Both mice are suitable for all grip types, but the GLORIOUS is more accomodating to a wider range of hand sizes overall.
Test Results
The Lowest Weight result is achieved with the small trap door covering the receiver storage compartment removed.
Cooler Master advertises the battery life on the Cooler Master MM731 is up to 190 hours connected via Bluetooth with LED lighting off and up to 72 hours connected with its USB receiver with LED lighting off.
The feet on the Cooler Master MM731 glide well on both mouse pads and directly on desks, but they make a slight scratchy noise on both, and the feet are thin compared to other gaming mice.
- Cooler Master MM731
- Wireless USB receiver
- Wireless USB receiver extender
- Trap door covering for USB receiver storage bay
- USB-C to USB-A charging cable
- Alcohol pad
- Adhesive L/R side grips
- Adhesive L/R click grips
- User documentation
You can reprogram all of the buttons on the Cooler Master MM731, including the scroll up/down inputs and the unlabeled button on the bottom of the mouse that cycles between CPI settings. You can also add a second layer of programmable commands by enabling the "Mouse Combo" button in the MasterPlus+ software. This "Mouse Combo" function reassigns the middle mouse button as a shift modifier you can hold down to activate the customizable secondary function of other buttons. Unlike other mice with comparable shift functions, the "Mouse Combo" button is automatically bound to the scroll wheel button, and you can't assign it to a button of your choosing. There's an additional switch on the bottom of the Cooler Master MM731 that changes between wireless connection modes and a non-programmable button for wirelessly pairing the mouse.
Note: Many users online have reported a range of issues with the Cooler Master MM731, including double-clicking, high motion latency, and high click latency. We did not experience these issues at any point on the unit we tested. Furthermore, we tested with the same website many users have been using to verify their double-clicking issues, and we didn't register a single double click with our unit. If you have this mouse and are experiencing issues, feel free to share your experiences in our discussions section.
The Cooler Master MM731 doesn't exhibit any problematic sensor tracking or speed variation issues.
The Cooler Master MM731 has generally low latency suitable for fast-paced games, but it shows small, intermittent latency spikes. These are unlikely to be noticeable for most users, but they may impact in-game consistency if you play at a high competitive level.
Note: Several other reviewers and owners of this mouse have reported sensor latency issues on earlier firmware versions. Many people report that these issues may be resolved by updating to newer firmware. We sold our test unit due to the product's age, and we can't verify this ourselves as of January 2026.
The available polling rate options on the Cooler Master MM731 are 125Hz, 250Hz, 500Hz, and 1000Hz; However, the polling rate is locked to 125Hz in Bluetooth mode. Cooler Master advertises that you can adjust the CPI up to 19000, but the software allows you to set the CPI as high as 38000. The sensor is also very far forward on the mouse, which may take some time to get used to.
