The catch
PetSafe ScoopFree Crystal Pro Legacy
Individual weights are not tracked.
Side by side
PetSafe Crystal Pro Legacy vs Litter-Robot 4 Compared: Litter-Robot adds cat weights in a taller box, and Legacy stays low and open
Quick verdict
A low open box for a cat that accepts crystals points to the uncovered Crystal Pro Legacy. Individual weight records and clumping-litter sifting, if the cat takes to the taller globe, point to Litter-Robot 4.
Before you buy
Why, and what it costs you
A low box can fit the room better than a globe full of features
Crystal Pro, uncovered, stands 6.2 in tall, and Litter-Robot 4 stands 29.5 in tall. The difference can matter under an open counter or in a small utility area. Leave the cat room above the tray and space to take it out. Neither overall height is a measured step-over height, and neither guarantees ease of movement.
Where this comes from
29.5 minus 6.2 equals 23.3 in of difference in overall height, which is not the same as a difference in entry height.
The catch
Whisker Litter-Robot 4 with Step and Waste Drawer Liners
Some cats may find the globe harder to accept, as it is much taller.
PetSafe ScoopFree Crystal Pro Legacy
- Why pick it
- Take the uncovered body, 6.2 in tall
- Monitor locally and keep controls simple
- The catch
- Individual weights are not tracked.
Whisker Litter-Robot 4 with Step and Waste Drawer Liners
- Why pick it
- Follow each cat's weight in the app
- Have compatible clumping litter sifted into a sealed drawer
- The catch
- Some cats may find the globe harder to accept, as it is much taller.
We may earn a commission from qualifying Amazon purchases. How we make money
What this page compares
Before you change a cat’s litter routine, compare low uncovered access, crystal-tray care and remote individual weight records.
A low open box for a cat that accepts crystals points to the uncovered Crystal Pro Legacy. Individual weight records and clumping-litter sifting, if the cat takes to the taller globe, point to Litter-Robot 4.
Which one fits
Pick the situations that sound like you
Need a low, uncovered body that fits under an open counter
The overall body of Crystal Pro is much lower.
- PetSafe ScoopFree Crystal Pro Legacy
- Better fit
- Whisker Litter-Robot 4 with Step and Waste Drawer Liners
- Caution
Need individual weight records I can see remotely
The connected weight system belongs to Litter-Robot 4.
- PetSafe ScoopFree Crystal Pro Legacy
- Not suitable
- Whisker Litter-Robot 4 with Step and Waste Drawer Liners
- Better fit
Want to stick with compatible clumping clay
Crystal Pro can't run without crystals.
- PetSafe ScoopFree Crystal Pro Legacy
- Not suitable
- Whisker Litter-Robot 4 with Step and Waste Drawer Liners
- Better fit
Prefer absorption in crystals over removing clumps
The crystals in Crystal Pro hold the urine, while the globe sifts clumps into a drawer.
- PetSafe ScoopFree Crystal Pro Legacy
- Better fit
- Whisker Litter-Robot 4 with Step and Waste Drawer Liners
- Caution
In practice
Differences you will notice
A low box can fit the room better than a globe full of features
Crystal Pro, uncovered, stands 6.2 in tall, and Litter-Robot 4 stands 29.5 in tall. The difference can matter under an open counter or in a small utility area. Leave the cat room above the tray and space to take it out. Neither overall height is a measured step-over height, and neither guarantees ease of movement.
How we worked this out
29.5 minus 6.2 equals 23.3 in of difference in overall height, which is not the same as a difference in entry height.
Moving to clumps changes the regular urine cleanup
The crystal tray in Crystal Pro soaks up urine, while Litter-Robot sifts suitable clumped waste into a sealed drawer. Litter-Robot is the pick if that liner-based routine suits you and your cat accepts the new litter. Crystal Pro is the pick if your crystal routine is already working and tray care is manageable.
How we worked this out
What the comparison is about is where waste stays between maintenance visits.
Several cats may call for more than a total visit count
Individual weight records and app access come with Litter-Robot 4, whereas Crystal Pro gives a local count. Litter-Robot is the pick if telling patterns apart cat by cat is part of how you supervise, though cats of similar weight can complicate attribution. Crystal Pro is the pick when regular direct observation and a simple count meet the household's needs.
How we worked this out
Litter-Robot 4 has documented individual weight tracking, and its attribution is not assumed to be infallible.
Option A
PetSafe, Crystal Pro Legacy
PetSafe ScoopFree Crystal Pro Legacy
Crystal is the documented litter fit, and the cabinet is 19.1 inches wide.
- Best for
- Take the uncovered body, 6.2 in tall
Facts we checked
- Box layout: Uncovered rake box in the checked exact ASIN
- Litter material: Compatible crystal litter only
- Overall dimensions: 27.6 x 19.1 x 6.2 in for the uncovered version
- Records: Local visit counter with no app
Option B
Whisker, Litter-Robot 4
Litter-Robot 4 with Step and Waste Drawer Liners
Automatic cycling starts at 3 pounds, and the cabinet is 22 inches wide.
- Best for
- Follow each cat's weight in the app
Facts we checked
- Box layout: Enclosed rotating globe with 15.75 in wide opening
- Litter material: Clumping clay recommended, with plant-based litters typically unsuitable
- Overall dimensions: 22 x 27 in footprint and 29.5 in overall height
- Records: App visit records and individual weight tracking
Spec by spec
Where they really differ
| Spec | PetSafe ScoopFree Crystal Pro Legacy | Whisker Litter-Robot 4 with Step and Waste Drawer Liners | In practice |
|---|---|---|---|
| Box layout | Uncovered rake box in the checked exact ASIN | Enclosed rotating globe with 15.75 in wide opening | Entering and turning feel different in a low open tray than in a globe. |
| Litter material | Compatible crystal litter only | Clumping clay recommended, with plant-based litters typically unsuitable | Part of the transition may be a change in material. |
| Overall dimensions | 27.6 x 19.1 x 6.2 in for the uncovered version | 22 x 27 in footprint and 29.5 in overall height | Both the height and the room for taking out the drawer or tray count. |
| Records | Local visit counter with no app | App visit records and individual weight tracking | Tracking individual weights is one thing, counting visits another. |
| Waste handling | Crystals absorb urine while the rake moves solids into the waste trap | Waste is sifted into a sealed drawer | Absorbed urine stays in the crystals, whereas clumped waste moves into a drawer. |
Trade-offs
What each pick costs you
With PetSafe ScoopFree Crystal Pro Legacy
- The tray keeps the urine absorbed until it is refreshed.
With Whisker Litter-Robot 4 with Step and Waste Drawer Liners
- You have to stay within the litter and cat-weight limits.
Change of plan
When the answer changes
You need low access with no cover
Go with PetSafe ScoopFree Crystal Pro Legacy. The open 6.2 in body belongs to the exact Legacy variant.
In my household of cats, tracking individual weights matters
Go with Whisker Litter-Robot 4 with Step and Waste Drawer Liners. Those app records come from Litter-Robot 4.
Decision guide
How to decide
The uncovered Crystal Pro Legacy suits a low open box and a cat that accepts crystals. Litter-Robot 4 suits individual weight records and clumping-litter sifting, as long as the cat accepts the taller globe.
A low box can fit the room better than a globe full of features
Crystal Pro, uncovered, stands 6.2 in tall, and Litter-Robot 4 stands 29.5 in tall. The difference can matter under an open counter or in a small utility area. Leave the cat room above the tray and space to take it out. Neither overall height is a measured step-over height, and neither guarantees ease of movement.
Moving to clumps changes the regular urine cleanup
The crystal tray in Crystal Pro soaks up urine, while Litter-Robot sifts suitable clumped waste into a sealed drawer. Litter-Robot is the pick if that liner-based routine suits you and your cat accepts the new litter. Crystal Pro is the pick if your crystal routine is already working and tray care is manageable.
Several cats may call for more than a total visit count
Individual weight records and app access come with Litter-Robot 4, whereas Crystal Pro gives a local count. Litter-Robot is the pick if telling patterns apart cat by cat is part of how you supervise, though cats of similar weight can complicate attribution. Crystal Pro is the pick when regular direct observation and a simple count meet the household's needs.
What this page can’t tell you
- Recommendations come from documented features and operating limits, not from any matched test of cleaning, noise or odor.
By the numbers
What the data shows
What we found across the automatic litter boxes we compare, plus the checked facts behind each finding.
Show the facts and the math
| Product | Needs it meets | Facts we checked | Sources |
|---|---|---|---|
| PetSafe ScoopFree Crystal Pro Legacy |
|
|
|
| Whisker Litter-Robot 4 with Step and Waste Drawer Liners |
|
|
|
Ready to buy
See today’s price and what owners say
Open either model on Amazon for the current price, customer reviews and delivery options.
PetSafe ScoopFree Crystal Pro Legacy
Take the uncovered body, 6.2 in tall
See price & reviews on AmazonWhisker Litter-Robot 4 with Step and Waste Drawer Liners
Follow each cat's weight in the app
See price & reviews on AmazonEach link opens in a new tab.
We may earn a commission from qualifying Amazon purchases. How we make money