Paw Ledger compares pet devices from the figures their makers publish, then does the arithmetic. This page sets out what we read, when, how devices are sorted and picked, what is missing, and what we never do.
What we read, and when
- 11 brand stores, 56 devices, read by script on November 7, 2026: whisker.com (Litter-Robot 4, 5, 5 Pro, EVO, Feeder-Robot), petlibro.com (13 devices), petsafe.com (9), catlinkus.com (9), petkit.com (9), neakasa.com (3), furbo.com (3), petcube.com (1), halocollar.com (2), fitracking.com (1), store.petlink.net (1).
- Prices: from each Shopify store's public
products.json(Petlibro, CATLINK, PETKIT, Neakasa, PetLink: the in-stock variant we name, for example the single set without ramp), from the price in the page's structured data (Whisker, Furbo, Fi), from Halo's store API, or from the product page text (PetSafe, Petcube). - Limits, capacities, refill intervals and plan prices: from each product page and each refill's own page, quoted in our data file with the sentence they come from. CATLINK product pages refused our reader that day; CATLINK figures come from the product descriptions in its store data.
- One seller per device. These brands sell direct and we list the brand's own store. Amazon, Chewy, Petco, Target and Best Buy also sell many of them; their pages could not be read by our script on November 7, 2026, so their prices are not compared.
What is not covered
- Brands not read yet: Tractive (its store showed euro prices only from where we read it), PetSafe's other feeders and fountains, Smarty Pear (Leo's Loo), uahpet, Meowant, Wyze, Eufy, SpotOn GPS fences, Garmin and Bluetooth tags. The comparison is not the whole market.
- Refill prices we could not find: PetSafe SmartSpin and OpenSky liners and deodorizers, PetSafe fountain filters, Neakasa M9 bags. Refills sold without an interval: CATLINK Pro series bags, PETKIT trash bags for the Max Pro 2, PETKIT refill rings for the Ultra. Plan prices not readable: Fi, PetSafe GPS, PetLink, PETKIT Care+.
- Bundles, ramps, steps, mats and accessories, color versions at the same price, reconditioned units.
- Noise, app quality, reliability and how pets react: we cannot know them without testing, and we do not test.
How the 3-year cost is computed
Device price + for each refill with a published interval, 3 x 365 days divided by the days one unit lasts, times the unit price (pack price divided by units in the pack) + required plans (optional plans only when you ask). We use the brand's interval for one pet, the low end when the brand gives a range (Petlibro's liners "once every 7 to 10 days": 7 days), and spread each pack over its units rather than rounding up. Litter you already buy, electricity, tax and shipping are left out. A device with a refill or a plan whose price or interval is not published is never ranked on 3-year cost: its total is shown with the missing part named.
How tables are sorted
By store price, cheapest first, unless the column says otherwise (3-year cost). A commission, present or future, never changes an order.
How each pick is chosen
"Our picks in 30 seconds" boxes follow one written rule: the cheapest device in our check that meets the stated condition, by store price or by 3-year cost when the badge says "over 3 years". A device picked once is not picked again in the same box. The conditions:
- Cheapest litter box over 3 years: every refill priced with a published interval.
- Cheapest for cats of 25 lb or more: published maximum cat weight of 25 lb or more.
- Cheapest rated for 4 cats or more: a published maximum number of cats (Whisker only).
- Cheapest with 2 weeks of waste capacity: the brand's own figure for one cat, 14 days or more, on a box using ordinary litter.
- Cheapest feeder with a camera; with two bowls; RFID (priced for two cats); single bowl (priced for two).
- Cheapest fountain over 3 years: filters priced with a published interval.
- Cheapest treat-tossing camera: camera alone, no plan.
- GPS: cheapest device; cheapest with a plan price we could read; cheapest with a published battery life of 30 days or more.
What we do not do
- We do not test, use or own these devices, and we never write "tested" or describe an experience we did not have.
- No star ratings, no scores, no customer reviews written, quoted or imported by us.
- No health claims. A brand's health or behavior feature is quoted as the brand's words, or left out.
- No discount percentage computed by us: a struck-through price appears only when the store shows a compare-at price.
- No fake urgency or stock counters.
How we are paid
We intend to apply to the affiliate programs of the brands that run one. If they accept, some links may earn us a commission when you buy, at no extra cost to you. Commissions are not part of any rule above. As of November 7, 2026, no program has accepted the site. Details: affiliate disclosure.
How often we update
Prices, refills and plans are read again at least once a month, and after the Black Friday and holiday sales, which were running when we read the stores. Each page shows the date it was last changed, and each price the date it was read.