Litter-Robot 3 vs 4: Specs Compared, and What Replaced LR3

You can’t buy a new Litter-Robot 3 Connect from Whisker any more. Whisker’s page says: “Litter-Robot 3 Connect is no longer available, but you can stop scooping with our new compact model, Litter-Robot EVO.” So the real question in “Litter-Robot 3 vs 4” is how a used or reconditioned LR3 Connect compares with the current LR4. By Whisker’s published specs, the LR4 has a wider, square entryway (15.75” x 15.75” against the LR3’s 10.25” opening) and a smaller footprint. It also has a 3 lb minimum cat weight for automatic mode, where the LR3 needs 5 lb. It lists at $699 as of November 2, 2026.

Why Whisker discontinued the LR3

Whisker’s FAQ says the Litter-Robot 3 and 3 Connect “were discontinued to make way for newer, more advanced models with improved features, quieter operation, and enhanced technology.” It points buyers to the EVO “for a similar experience” or to the Litter-Robot 5.

Litter-Robot 3 Connect vs Litter-Robot 4: specs

Entryway note: Whisker gives three versions of the LR3 opening:

• the spec tab says “10.25” x 15.25""
• the FAQ says “16”H x 10.25”W”
• the manual (p. 9) says “15.50” x 10.25""

The width, 10.25”, is the same in all three. We couldn’t verify a single height figure.

Manual note: the manual we used is titled “Litter-Robot 3,” not specifically “Connect.” Whisker’s LR3 Connect page links to that support page for its manual.

What Whisker says changed

Whisker’s FAQ comparing the two says the LR4 adds:

• the optional OdorTrap system
• the “SafeCat System with OmniSense® Detection” for safety and “real-time tracking of waste and litter levels”
• a “QuietSift® cleaning cycle”
• “an enlarged waste drawer”
• “a wider opening”

In the specs, the biggest physical differences are the entryway shape and the minimum cat weight. On weight, Whisker’s LR3 manual (p. 5) says “Cats must weigh 5 pounds or more to safely use the Litter-Robot in Automatic Mode,” while the LR4’s lower threshold is 3 lb. For lighter cats, Whisker recommends semi-automatic mode on both. At the top end, Whisker described the LR3 as having no weight limit, while the LR4 is rated for 3–25 lb. See large cats.

Considering a used or reconditioned LR3

• Whisker’s own reconditioned units: Whisker says its reconditioned products “are generally sold as new and then returned under our 90-day in-home trial” and are “reconditioned and tested to verify they meet original factory specifications.”
• Price and stock: the reconditioned LR3 Connect page listed it “As low as $449” with WhiskerCare 1-Year Warranty coverage. On Whisker’s reconditioned listing for November 2, 2026, though, the LR3 Connect showed as Out of Stock. The LR4 reconditioned was listed at $664 against $699 new.
• Existing warranty: Whisker says a WhiskerCare warranty “remains active for 1 year (or 3 years if you purchased the extended warranty) from the date your product was shipped.”
• Private-sale units: the pages we checked don’t say whether that coverage transfers to a second owner. Ask Whisker support before buying one.
• Supplies: Whisker’s current carbon filters are “Not compatible with Litter-Robot 3/Connect.” The LR3 uses its own filters, which Whisker still listed at $30 for a 6-pack.
• Liners: the LR3 manual says “any 38-49-liter trash bag will also work” in place of Whisker’s liners.
• Problems: contact Whisker’s support; don’t attempt repairs beyond what the manual describes.

What replaced it: the EVO

Whisker positions the Litter-Robot EVO as the LR3 Connect’s successor. It calls the EVO “a similar experience at a similar price point.”

By these specs, the EVO is smaller and lower in price than the LR4. Whisker rates it for fewer and lighter cats than the LR3 Connect claimed. The LR4 is the current model that matches the LR3’s four-cat claim. See the Litter-Robot 4 page and alternatives.

Bottom line

Whisker has discontinued the Litter-Robot 3 Connect, and its reconditioned LR3 was out of stock on November 2, 2026. Against the LR3, the LR4 has a wider square opening, a smaller footprint and a 3 lb automatic-mode minimum instead of 5 lb, at $699 list. If you’re weighing a used LR3, check what warranty remains from its ship date and plan on LR3-specific filters. Compare running costs in the cost calculator.