Chinese zodiac compatibility, in the narrow sense used by this two-rule browser, is a binary classification of a pair of animals against exactly four three-member San He trines and six direct Liu Chong oppositions. A trine label means the two chosen animals are distinct members of the same three-animal group out of four fixed groups in the 12-year cycle. An opposition label means the pair is one of six fixed pairs that sit directly across the cycle. Every other combination is labelled as not classified by this limited two-rule model. The classifier does not produce a percentage, a ranking, or a forecast about a friendship, family tie, or partnership. It also does not derive an animal from a Gregorian year, because selecting two known animals directly keeps the relationship table separate from the calendar conversion that handles the Lunar New Year boundary. The point of the tool is to show what the two named folk rules actually say, and what they do not say, with every input, group, and pair visible to the reader.
Why the model is narrow, not universal
The phrase "Chinese zodiac compatibility" covers many different folk traditions that do not all agree on which pairs are harmonious, harmful, or neutral. Some sources discuss Six Harmonies, harms, punishments, Five Elements balances, or relationships among the year, month, day, and hour branches. Others list additional conflict traditions with their own named pair sets. A page that merged all of these into one table would imply a false universal classification. Instead, the Chinese Zodiac Compatibility browser restricts itself to two named rules that have stable English-language documentation: the four San He trines and the six Liu Chong oppositions. The visible limitation statement on the page says the same thing: year-animal matching is not a scientific measurement and should not substitute for a full BaZi or Four Pillars analysis. A focused guide on how those two rules were chosen is in Chinese Zodiac Compatibility Accuracy: Two Sourced Rules.
The four San He trines
Each San He trine is a fixed three-animal group. Any two distinct animals drawn from the same group receive the label "Traditional trine (San He)". Across the four groups there are exactly twelve unordered trine pairs in total, which works out to 3 unordered pairs per group × 4 groups = 12. A sign paired with itself is not treated as a two-sign trine pair. The groups are listed below in the canonical 12-position cycle order used by the interface.
| Trine group | Members |
|---|---|
| Group 1 | Rat, Dragon, Monkey |
| Group 2 | Ox, Snake, Rooster |
| Group 3 | Tiger, Horse, Dog |
| Group 4 | Rabbit, Goat, Pig |
The six Liu Chong oppositions
Each animal has exactly one opposite in this narrow model. The six opposition pairs sit directly across the 12-position cycle and never overlap the trine pairs. The result is symmetric: pairing animal A with animal B returns the same label as pairing animal B with animal A, which is why the browser offers a Swap control for visual confirmation.
| First animal | Direct opposite |
|---|---|
| Rat | Horse |
| Ox | Goat |
| Tiger | Monkey |
| Rabbit | Rooster |
| Dragon | Dog |
| Snake | Pig |
How to compare two animals
- Choose two already-known Chinese zodiac animals directly from the two selectors. The order is Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, and Pig. This browser does not calculate signs from Gregorian years or birth dates, so both animals must be entered by hand. If a user does not already know their own animal, the related Chinese Zodiac Calculator maps a supported year to an animal while flagging the Lunar New Year boundary, which is a separate task handled by a separate tool.
- Read the result line. The page classifies the pair into one of three states: Traditional trine (San He), Direct opposition (Liu Chong), or Not classified by this limited two-rule model. Each profile next to the selectors also displays the selected animal's complete trine group and direct opposite, so the badge can be checked against the raw reference data without trusting it alone. That side panel is the fastest way to confirm whether the classifier has applied the two rules correctly.
- Use the Swap control to exchange the two values in one action and confirm that the classification is symmetric. Swapping does not change the sourced label; it only reverses the display order of the two animals. Both selectors are native controls with a 44-pixel minimum height, and the layout stacks cleanly on narrow screens without a drag gesture, so the comparison can be repeated from either direction in one tap.
What "not classified" actually means
From 12 distinct animals there are 66 unordered pairs (12 × 11 ÷ 2 = 66). Of those, 12 are trine pairs and 6 are opposition pairs, leaving 48 pairs (66 − 12 − 6 = 48) labelled as Not classified by this limited two-rule model. The phrase is intentional. It does not mean neutral, compatible, incompatible, safe, ideal, or doomed. It only means the pair does not fall under the two sourced rules the browser is built to show. Broader traditions may classify those same 48 pairs under Six Harmonies, harms, punishments, or element relationships, but the browser deliberately does not merge those sources. Readers who need a broader judgment should consult a practitioner who works with the full Four Pillars chart, which considers year, month, day, and hour branches together rather than the year branch in isolation.
What the browser does not do
For contrast, here are several things the tool is built not to do, all of which are written into the visible limitation statement and the implementation methodology.
- No calendar conversion. The browser does not derive an animal from a Gregorian year, so there is no Lunar New Year boundary to worry about. For year-to-animal lookup, the related Chinese Zodiac Calculator is the correct tool, and the two interfaces deliberately share the same 12-position cycle order to keep that handoff consistent.
- No invented score. The classifier returns one of three text labels and nothing else. There is no percentage, rank, star count, or weighted sum, and the folk rules are not turned into a numeric output. A folk classification is preserved as a folk classification.
- No personal data. The tool does not request a name, birth date, gender, location, relationship history, account, upload, or network call. The two selections live only in React page state and are not persisted to local storage, cookies, or any backend service.
- No silent aliasing. Source aliases such as Mouse, Cow, Sheep, or Ram exist only to reconcile literal fixtures during verification. The user-facing controls always use the canonical English labels Rat, Ox, and Goat. Cat, Boar, and other regional substitutions are not silently treated as equivalent, because those variants require a separately declared cultural scope that this browser does not assume.
- No scientific claim. The visible limitation statement reminds readers that year-animal matching is not a scientific measurement and should not guide consequential relationship decisions on its own, no matter how the two named rules classify the pair.
How the rules stay separated on the page
The two rules are presented as separate, non-overlapping reference tables rather than blended into one combined grid. A trine pair is drawn from inside one of the four three-member groups, while an opposition pair is drawn from the six two-member direct pairs that span the cycle. Because the trine groups and the opposition pairs are stored as literal independent fixtures, the same animal can be a member of one trine group and exactly one opposition, but no animal can ever be classified as both at the same time for the same pair. The browser enforces that separation by design: any given pair of distinct animals receives exactly one of the three possible labels, and the label is computed by checking the trine membership first, then the opposition map, then defaulting to the unclassified phrase. This is why the result is purely a classifier rather than an evaluator; the tool does not weigh a trine match against an opposition, because the two rules never share a pair.
Source note
The 12-position cycle used by both this browser and the related Chinese Zodiac Calculator is documented by the Hong Kong Observatory's 12-Year Animal Cycle page, and zodiac compatibility traditions are described in the National Folk Museum of Korea's Harmony of the Zodiac Animals reference. The browser restricts itself to the two named rules that are most consistently documented in English-language sources, and it shows the classification directly rather than blending folk traditions into a single synthetic score.