Both the Logitech Lift and the Logitech MX Anywhere 3S are wireless mice from the same manufacturer, and both record Bluetooth Low Energy and Logi Bolt connectivity. Neither is a light mouse in the ordinary sense. The difference is where the weight goes. The Lift is recorded as a vertical ergonomic wireless mouse with a natural handshake grip angle, a grip angle of vertical at 57 degrees, a weight of 125 g and an intended hand size of small to medium. The MX Anywhere 3S is recorded as a compact wireless mouse intended for travel, weighing 99 g on the product page, with recorded support for glass and most surfaces.
Those are two different ways of fixing an uncomfortable hand position. The Lift changes the angle the forearm sits at. The Anywhere 3S changes how little the mouse weighs and how little desk space it needs. A buyer choosing between them is choosing which discomfort they would rather have.
Every value here comes from the specifications recorded against each product, with the manufacturer page it was read from. No mouse was measured for this comparison, so there is no claim about tracking behaviour on any surface, button feel, or how either mouse feels over a long session.
What actually differs
Grip angle. The Lift records its grip angle as vertical, 57 degrees, and vertical grip appears in its recorded feature list, so the forearm sits in a handshake position rather than flat on the desk. The MX Anywhere 3S records no grip angle at all, and its recorded description calls it a compact mouse intended for travel, so the recorded difference between the two is the shape of the hand position rather than the size of the mouse.
Intended hand size. The Lift records its intended hand size as small to medium, and its recorded description says the same thing. The MX Anywhere 3S records no hand size, so it is not a mouse recorded for a particular grip.
Weight. The Lift records 125 g and the MX Anywhere 3S records 99 g on the product page, while its support specification records 95 g with the battery, a point the catalogue marks as conflicting. For a mouse that moves across a large display, or that gets packed and unpacked every day, the difference is noticeable. For a mouse that stays beside one keyboard, the heavier body is the more stable one to move.
Buttons and sensor. The Lift records 6 buttons and a sensor resolution of 1000 DPI nominal, adjustable from 400 to 4000 DPI. The MX Anywhere 3S records 6 buttons and a sensor resolution of 200 to 8,000 DPI on the product page, while the support specification records 400 to 8,000 DPI, again recorded as conflicting. The button count is the same, so the difference is in how finely the mouse can be set.
Surface support and battery. The MX Anywhere 3S records support for glass and most surfaces, and a battery life of up to 70 days on a full charge. The Lift records no surface support value, and its recorded battery life is up to 24 months on one AA battery, which is a different arrangement rather than a longer or shorter run time.
Size. The Lift records 108 by 70 by 71 mm. The MX Anywhere 3S records 100.5 by 65 by 34.4 mm, which is a fraction of the height and a fraction of the bulk.
Who should pick which
Choose the Lift if your hands are small to medium, if the mouse is used for long stretches, and if the wrist and forearm position is the part of the setup that bothers you. Its recorded 57 degree vertical grip, its recorded multi-device switching and its recorded 24 month battery on one AA are the reasons to accept a 125 g mouse and a tall narrow footprint.
Choose the MX Anywhere 3S if the mouse moves between locations, if you work across more than one surface including glass, if the recorded 99 g matters, and you want the recorded battery figure of up to 70 days on a full charge. Its recorded compact body is what makes it a travel mouse rather than a desk mouse.
The Lift is the wrong answer for someone who wants a light travel mouse, and the MX Anywhere 3S is the wrong answer for someone whose hand position is the problem, since it records no vertical grip.
What this comparison does not settle
It does not settle price, because no price is recorded for either mouse. It does not settle tracking behaviour on any surface, or how either mouse feels in the hand over a long session, because no mouse was measured. It does not settle the MX Anywhere 3S weight or sensor resolution precisely, because the catalogue records both as conflicting between the product page and the support specification. It settles grip angle, hand size, recorded weight, buttons, recorded sensor resolution, battery arrangements and recorded size, which is enough to separate a vertical ergonomic mouse from a compact travel mouse without declaring either of them better in general.