How we compute a match.

Most of the "which cat should I choose" guides you will find online fall into one of three traps. The first: they confuse popularity with compatibility. You get offered a Maine Coon because it is the most adopted breed, not because it fits your home, your budget, your activity level or your experience.

The second: they reason in binary categories ("small cat", "family with children", "lap cat") where reality is continuous. An 8 kg Maine Coon is not a cuddly "big cat": it is an indoor athlete that asks for 30 minutes of active play a day and vertical space. The word "big" hides the data that matters.

The third: they never explain their criteria. You read that "the Maine Coon suits families" without knowing whether the author accounted for the HCM (hypertrophic cardiomyopathy) predisposition, for which genetic screening at the breeder is recommended, and which can weigh heavily on the veterinary cost of a feline lifetime, or whether they simply copied the FIFe page.

CatMatch starts from the opposite principle: every breed is scored on 15 axes from 1 to 5, your answers build an ideal profile on those same 15 axes, and we compute the distance between the two. No magic, just transparent arithmetic, with verifiable data and a method documented publicly on this page.

In practice, the algorithm runs in four steps:

(1) Hard filters. Before any score is computed, three answers act as strict, disqualifying filters. A declared allergy only keeps hairless breeds (level 1) and breeds reputedly better tolerated (level 2), 10 breeds out of 77; none is guaranteed reaction-free. Living with a dog rules out breeds that get on poorly with other species. A tight monthly budget rules out the very large breeds (Maine Coon, Savannah and the like), heavier to feed and to care for, through a weight cap. Everything else, space, talkativeness and energy, eliminates nobody: those criteria weight the score (step 3) rather than exclude, because a Maine Coon can live perfectly well in an apartment with enough vertical enrichment, and a talkative Siamese will suit anyone who enjoys the conversation.

(2) Ideal vector. Your quiz answers feed a 15-dimensional vector: energy, exercise, tolerance of children, space needed, and so on. Each option of each question pushes every one of those 15 axes up or down, following modifiers defined in questions.json. Ticking "activity 5/5" pushes ideal energy toward 5 and exercise toward 5. Ticking "first cat" lowers ideal trainability (you need a cooperative breed) while keeping the need for attention.

(3) Weighted Euclidean scoring. For every breed that survives the hard filters, we compute the weighted Euclidean distance between its native profile (the 15 scores of 1 to 5 taken from the literature) and your ideal vector. The weighting (see section 5) reflects how much each axis bears on real quality of life. The final score is normalized to 100, where 100 would be a theoretical perfect match (never reached in practice: no breed is exactly you).

(4) Sorting and tie-break. Breeds are sorted by descending score. Ties are broken by popularity in France (LOOF data), not because popularity is a quality criterion, but because it is a reliable proxy for the availability of serious breeders and of general veterinary support for that breed.

Every breed in the catalog goes through a structured extraction protocol based on four primary sources:

• FIFe (Fédération Internationale Féline), the official standard for each breed: size, weight, life expectancy, temperament as defined by the country of origin. FIFe nomenclature
• LOOF (Livre Officiel des Origines Félines), France-specific data: registration statistics, official recognition status, and the breeder network. LOOF
• TICA (The International Cat Association), the American Breed Standards, more detailed on behavioral traits and health tendencies. Used as a complement when the FIFe page stays terse. TICA Breeds
• French Wikipedia, for verifiable figures (average weight, life expectancy, genetic prevalence) always cross-checked against the primary sources. Never used on its own for a subjective trait.

For behavioral traits absent from the official standards ("easy to train", "tolerance of children"), we rely on published behavioral studies and veterinary consensus. When sources disagree, we record the median and flag the discrepancy on the breed page.

The quiz is not an individual predictive test: it is a classifier of breeds relevant to your profile. The distinction matters.

A Maine Coon is not a guaranteed match just because it comes out first. Every kitten is singular, the temperament of the line counts, and the early socialization you give it counts even more. The quiz points you toward a breed that is statistically consistent with your life; choosing a specific individual is still something you do at the breeder or the shelter, by spending time with the kitten and its mother.

The quiz does not capture love at first sight. If you grew up with a Birman and that is the one calling you, no algorithm should talk you out of it, unless there is an objective dealbreaker (allergy, budget incompatible with veterinary costs, unsuitable home).

The quiz does not replace a veterinary assessment or a conversation with a feline behaviorist. If your situation is unusual (a very young child, an adult cat already at home, a respiratory allergy), go and see a professional who will meet your family before confirming the choice.

We also have structural biases. The catalog is mostly made of breeds recognized by FIFe and TICA, so European and American ones, with a few Asian breeds. Non-standardized primitive breeds (village cats, landrace breeds) are not covered. If you adopt from a shelter, the quiz will give you an idea of the traits compatible with your profile, but the on-site assessment by the volunteers will always come first.

The 15 axes do not all carry the same weight in the final score. A bad match on talkativeness (a very vocal Siamese with someone looking for quiet) or on independence weighs heavily; a bad match on cold tolerance only matters at the margin in mainland France. The weighting below reflects those differences.

How we calibrated those weights. A first version based on veterinary consensus and behavioral literature (heavy weights for the feline pivots, that is talkativeness, independence and grooming, light weights for climate tolerance in a temperate climate and for energy and exercise, since a cat's activity is mostly self-triggered). Validated with synthetic personas: 18 user profiles built by hand (urban young professional, rural family of three children, senior in an apartment, and so on), each with a known expected answer. We iterate on the weights until at least 12 personas get a top 3 judged plausible on manual review.

Three operating commitments, for as long as this site exists:

(1) Every calibration change is public. If we change a weight, a hard filter or the modifiers of a question, it is announced at the top of this page with the date and the reason. Your results may legitimately change between two visits, and you will know why.

(2) No breeder promotion influences the ranking. We accept neither money nor breed placement. The only monetization considered (never switched on without notice) is affiliation on generic utility products (litter, carriers, insurance), which creates no bias on the breed ranking.

(3) Your data stays local. Your quiz answers are stored in localStorage, on your device, never sent to a server. You can erase them at any time from your browser settings. We run no intrusive analytics and there is no user account.

A ranking looks wrong to you? Challenge it. Every reasoned report is checked against the sources, and the page is corrected if you are right: it is our best calibration loop. A question, a breed missing from the catalog? Same door: the contact page.