Quick answer: The best GPS tracker for cats is lightweight (under 35g), has a long battery life, and works without a subscription or with a low monthly fee.
Cats carry trackers on their collar. Anything over 35g will bother most cats and can be dangerous if it gets caught on something. Look for trackers designed specifically for cats, not adapted dog trackers that are too heavy.
Cellular GPS works everywhere but requires a monthly subscription. Bluetooth community network trackers like Apple AirTag have no subscription but rely on nearby phones to relay location — works well in urban areas, much less reliable in rural ones.
Cat trackers are harder to recharge than dog trackers since cats often resist handling. Look for models that last at least 5-7 days on a single charge to minimize how often you need to catch your cat.
For outdoor cats, a lightweight cellular GPS tracker on a safety breakaway collar is the safest combination. In dense urban areas, an AirTag is a low-cost alternative.