Package identity
Read the full Free & Clean name
- Can support
- The exact standard-weight or lightweight SKU shown on the current package.
- Stop transfer when
- Free & Clean is mentioned without confirming whether Lightweight appears on the bag.
Exact SKU comparison
Tidy Cats Free & Clean standard vs lightweight in Litter-Robot 4
The names are similar, but only the standard-weight formula has an accepted exact LR4 report; the lightweight formula remains Estimated.
Decision rail
Four checks, in order
Passing one check does not override a failure or unknown in the next. This is a compatibility decision, not a popularity ranking.
- 01Package
Read the weight variant
The shared Free & Clean name is not enough; confirm whether Lightweight appears on the current bag.
- 02Rule
Apply standard weight explicitly
The maker’s preferred combination includes standard weight, so the lightweight variant starts from a different boundary.
- 03Report
Keep the positive signal on one SKU
Works fine was reported for the standard formula only and does not fill missing lightweight evidence.
- 04Change
Recheck renamed packages
A package or formula update can break even a previously valid exact-SKU match.
Evidence transfer ledger
How far this evidence can travel
A report stays attached to the identity and conditions it actually names. Each unresolved mismatch stops transfer; similarity alone does not fill the missing field.
Official class
Retain the weight distinction
- Can support
- Standard-weight clay as the maker's preferred starting class; lightweight as a separate estimate.
- Stop transfer when
- Shared clay and clumping labels are used to erase the standard-weight requirement.
Public report
Attach works fine only to the standard SKU
- Can support
- One narrow positive single-report signal for Free & Clean Unscented Clumping.
- Stop transfer when
- The comment is copied to Free & Clean Lightweight Unscented or treated as long-term proof.
Unknown outcome fields
Leave duration and failure modes unfilled
- Can support
- A transparent record that states what the source did and did not report.
- Stop transfer when
- Missing dust, tracking, sticking, sensing, or maintenance observations are interpreted as no problem.
Current formula
Recheck dated package and source
- Can support
- Transfer to a current bag only when the identity and key specifications still match.
- Stop transfer when
- A redesign, rename, weight claim, or formulation difference cannot be reconciled.
Source continuity review · 2026-10-15
Can the older evidence describe today's bags?
This editorial check joins dated manufacturer-source status to already accepted exact-product records. It is not a new PawExact test, a rereading of old household posts, or proof of formula continuity.
- Dated source state
- Purina's linked standard-weight Free & Clean page returned 403 locally and from OVH on October 14; the lightweight variant has no accepted exact LR4 use report in this catalog.
- Exact evidence unit
- The one brief positive LR4 report belongs to standard-weight Free & Clean only. The lightweight row remains a rule-based estimate, not a second observed trial.
- First comparison
- Check the weight wording and full unscented formula on each bag; hold physical fill, cycle delay, and liner state before comparing a switch.
- Stop transfer when
- Do not transfer the standard bag's owner report to the lightweight variant or infer that equal bag weight means equal fill volume.
Published boundary
What Litter-Robot actually says
These statements describe classes and limits. They are not PawExact tests and do not automatically approve every product using the same marketing term.
OfficialLitter-Robot 4
“We recommend a high-quality, standard-weight, clay-based clumping litter”Official source
OfficialLitter-Robot 4
“Litters that do not work in Litter-Robot are the strictly absorbent, non-clumping or loose-clumping litters, newspaper-based litters, and absorbent wood pellet litter.”Official source
Exact-product records
Products that show why the class label is not enough
This comparison exists to prevent family-name transfer. A report for the standard bag is not evidence for the lightweight bag.
Single report1 public report
Free & Clean Unscented Clumping
Purina Tidy Cats
- Material
- Clay
- Clumping
- Clumping
- Weight
- Standard
One accepted exact LR4 report gives a narrow positive signal without duration or detailed failure-mode observations.
Likely compatible
Read exact recordEstimatedClass rule only
Free & Clean Lightweight Unscented
Purina Tidy Cats
- Material
- Clay
- Clumping
- Clumping
- Weight
- Lightweight
No accepted exact LR4 report is recorded; its current result is Estimated.
Compatible with conditions
Read exact recordBefore a larger purchase
A small, observable first-use check
This is not a controlled test protocol. It is a way to notice an obvious mismatch before treating one successful cycle as proof.
- Check 1Confirm the complete bag name and whether it says Lightweight.
- Check 2Compare material, weight, clumping, and particle form rather than brand family alone.
- Check 3For a trial, inspect clump release, screen loss, dust, tracking, and level readings separately.
- Check 4Submit a lightweight report only when the exact machine and exact lightweight formula are explicit.
Known limits
What the current evidence cannot prove
- The standard formula has one accepted report; the lightweight formula has none.
- PawExact has not measured density or performance differences between the two bags.
- The available report cannot establish long-term dust, tracking, sticking, or maintenance for either variant.
Evidence readiness
What this guide can support today
This checkpoint separates a useful answer from claims the current official rules and exact records still cannot support. It is an editorial evidence review, not a PawExact test.
- Question scope
- This page prevents transfer between standard and lightweight Free & Clean bags in LR4. It is a variant-identity comparison, not a measured equal-volume performance experiment.
- Direct official boundary
- LR4's preference includes standard weight and clay clumping together. The standard bag matches the recorded baseline, while the lightweight bag remains outside the weight preference despite sharing a family name.
- Exact-product evidence
- One accepted exact LR4 report says the standard-weight formula worked fine but omits duration and detailed outcomes. The lightweight formula has no accepted exact-pair report and stays Estimated.
- Remaining gap
- There is no direct lightweight observation, density measure, or same-home comparison. The rule is useful but strongly overlaps the general weight-class guide and both product records.