Devario fangae shares uniquely with D. browni and D. kakhienensis in having an anterior expansion in width of the P stripe. It is distinguished from both species in having a broad P stripe, wider than adjacent interstripes (vs. narrow, as wide as or narrower than interstripes). It is further similar to species of Devario characterized by three dark stripes (P, P+1, P-1) along the side, but can be differentiated from these in having all three stripes wide and of similar width (vs. P stripe wide and P+1 and P-1 stripes much narrower as in D. aequipinnatus, D. acrostomus, D. deruptotalea, D. fangfangae, D. fraseri, and D. gibber). Both D. regina and D. malabaricus possess stripes that are relatively wide but not wider than interspaces and the P stripe is split anteriorly by a short light interspace.
Both D. assamensis (Barman, 1984) from the Brahmaputra River in southern Assam, and D. ostreographus (M’Clelland, 1839), without locality, are extremely deep-bodied, and thus can be easily distinguished from D. fangae. D. fangae differs from D. devario by having infraorbital process and rostral barbell (vs. absent); distinct danionine notch (vs. very shallow); dorsal fin rays with 9½-11½ rays (vs. 15½-17½ rays); lateral line with 30-32 scales (vs. 42-47); and 12 circumpeduncular scales (vs. 16). D. fangae can be differentiated from nominal species D. affinis, D. annandalei, D. strigillifer, D. spinosus and D. yuensis in Myanmar by having fewer scales in the lateral line (30-32, vs. 35-53); fewer circumpeduncular scales (12 vs. 14-20); and absence of a supraorbital process. It can be separated from D. xyrops in having a continuous P stripe (vs. P stripe separated into two blotches); and from D. myitkyinae by the color pattern consisting of three dark, straight horizontal stripes on the middle of the side (vs. up to five irregular stripes), branched dorsal-fin rays 9½-10½, exceptionally 11½, vs. 11½-13½, exceptionally 10½, and branched anal-fin rays 9½-11½ vs. 12½-13½, exceptionally 11½ or 14½. Devario fangae can be distinguished from all remaining species of Devario also by the striped color pattern (vs. a pattern of large blotches as in D. kysonensis, D. pathirana, or smaller blotches as in D. quangbinhensis; a very narrow posterior P stripe as in D. chrysotaeniatus, D. laoensis, D. leptos, D. micronema, D. neilgherriensis; vertical bars as in D. apogon, D. apopyris, D. auropurpureus, D. interruptus, D. jayarami, D. maetaengensis, D. salmonatus, D. shanensis; uniform, with or without a thin dark stripe posteriorly on the side as in D. acuticephala and D. sondhii; P stripe separated into two blotches as in D. anomalus; or wide P stripe posteriorly on side, but no other dark stripes as in D. naganensis). D. fangae differs further from barred devarios, D. fraseri, and D. malabaricus, by having infraorbital process (vs. absent) (Ref. 117334).