Why material fit is more than one property
A filament's marketing sheet usually leads with a single headline trait: PETG is "tough," ABS is "heat resistant," PLA is "easy to print." A real part rarely faces one condition in isolation. A phone mount lives near a sunny window (heat and UV together), a garden tool handle gets wet and handled roughly (moisture and impact together), and a kitchen gadget sits near a dishwasher (heat and moisture together). This tool scores each filament family against the specific combination of conditions you describe, rather than ranking families by a single trait.
How the comparison works
Six common desktop-FDM families are scored against your entered heat, UV, moisture, and chemical-contact ratings, plus whether the part needs to flex. A family that clearly mismatches one condition, such as PLA in a high-heat, high-UV outdoor role, is scored down rather than excluded outright, so you can see how close a runner-up is. The result names a best-fit family and a genuine alternative, not just a single "correct" answer, because two families are often both reasonable once you decide which tradeoff you would rather accept.
Worked example
An indoor decorative bracket, low heat, low UV, no chemical contact, rigid: the tool returns PLA as the best fit, since it is the easiest of the six families to print reliably and none of the entered conditions push against its weaknesses. PETG appears as the alternative, worth choosing if the bracket might get bumped or see occasional heat you have not accounted for, at a small cost in print-tuning difficulty.
Limitations
This is a planning-level comparison between six common families, not a database of every filament brand or a substitute for that brand's own datasheet. It does not know your actual printer's calibration, your specific filament's true properties, or your part's true safety requirements. Confirm heat and chemical limits against a real datasheet, and test a small coupon before committing a part where a wrong material choice would be costly or unsafe.