对甲基红是一种化学物质，分子式是C15H15N3O2。

C.I. Acid Red 2; C.I. Acid Red 2 (8CI); O-Methyl red; CI NO 13020; BROMOCRESOL GREEN-METHYL RED; BROMOCRESOL GREEN-METHYL RED ETHANOL; BROMOCRESOL GREEN/METHYL RED, MIXED INDICATOR; BROMOCRESOL GREEN/METHYL RED, MIX INDICATOR FOR ALKALINITY; METHYL RED INDICATOR; METHYL RED MIXED SOLUTION; 2-{(E)-[4-(dimethylamino)phenyl]diazenyl}benzoic acid; 5-(dimethylamino)-2-[(E)-phenyldiazenyl]benzoic acid

密度：1.17g/cm3

熔点：178-182℃

沸点：486.2°C at 760 mmHg

闪点：247.8°C

蒸汽压：2.89E-10mmHg at 25°C