How we judge whether a robot fits

The fit rules

• A hard limit your house exceeds excludes the unit. Lawn area, slope, pool length, pool type, cat weight, cat count, threshold height, litter type, a boundary wire when you said no wire, a wanted mop when there is none.
• Within 10% of a hard limit is “fits, at a limit”. Makers rate area and slope under their own conditions; a house at the edge of the rating is a house that will find out.
• A wanted feature the unit lacks is “at a limit”, not excluded: wall climbing, cordless, a self-emptying dock, multi-zone mowing, an anti-tangle brush in a pet home, a mop that lifts over carpet.
• A limit the maker does not publish makes the verdict “unknown”, never “fits”.

The same rules run in your browser on every guide (“Adjust to your house”) and at build time; parity tests hold the two to the same answers.

How we decide a fact is solid

• A limit is recorded only when it appears on the maker’s product page, spec sheet, FAQ or manual, with the URL and the verbatim sentence stored beside it. A checker re-fetches every source and looks for the sentence; a fact it cannot find again is never rendered.
• Figures seen only in a listing, a search snippet or a review are not recorded as specs. Tester measurements are shown separately, named and linked.
• We do not borrow a figure from a sibling model. A missing field stays missing.
• We do not test units ourselves, and every page says so.

Currently 138 units and 1336 cited limits.

How to read the tables on our best and compare pages

• “Not published” means the maker’s page we read does not state the figure. It is a gap in what the maker publishes, not a zero. We never fill it from a sibling model.
• A bare price is what the Amazon listing we verified showed on the date printed beside it. Prices change; the listing shows today’s.
• A price marked “list” is the maker’s own list price. We show it only where no Amazon listing passed our check.
• “No price published” means the maker states no price and we link no Amazon listing for this exact model, so there is no Amazon link.
• Refill costs are the maker’s own refill packs at the Amazon price on the checked date, times how often the maker says to replace each part. If the maker does not publish how often, or we found no listing for the maker’s own part, the page says “not published”. We never estimate.
• Owner reports and tester figures sit on each model page, each linked to where it was read. The best and compare pages keep to the picks, the tables and the verdict.

How we match an Amazon listing

A search for any model returns bundles, last year’s model under a similar name and, often, the same unit under two listings at different prices. We link only a listing whose own title and model number match the bare unit, sold new. We skip renewed and used listings, bundles, parts, and similar names.

Each model page lists real listing titles we skipped and why. Before you buy, check that the seller is the maker or Amazon itself, and that the model number on the box matches the one on our page.

What we will never rank

A unit whose model or its family appears in a CPSC recall is shown for research but never picked and never linked until the maker’s remedy is documented.

How the site makes money

Amazon links earn us a fee, and the site footer says so on every page. The picks come from the rules above; a commission cannot move a unit past a limit it misses. The disclosure.