All that glitters is not gold

Meaning: Appearances can be misleading.

Origin: Shakespeare's The Merchant of Venice (c. 1596) has "All that glisters is not gold" on the scroll inside the golden casket, which a suitor wrongly chooses. The idea is much older: Chaucer's The Canon's Yeoman's Tale says that not everything that shines like gold is gold.

Equivalents in French, Spanish, Japanese, German, Italian, and 5 more languages

French: Tout ce qui brille n'est pas or (literally: All that shines is not gold)
Spanish: No todo lo que brilla es oro (literally: Not everything that shines is gold)
Japanese: 光るもの必ずしも金ならず (Hikaru mono kanarazu shimo kin narazu) (literally: Things that shine are not necessarily gold)
German: Es ist nicht alles Gold, was glänzt (literally: Not everything that shines is gold)
Italian: Non è tutto oro quel che luccica (literally: Not all is gold that glitters)
Portuguese: Nem tudo o que reluz é ouro (literally: Not everything that shines is gold)
Dutch: Het is niet al goud wat er blinkt (literally: Not all is gold that gleams)
Russian: Не всё то золото, что блестит (Ne vsyo to zoloto, chto blestit) (literally: Not all that glitters is gold)
Polish: Nie wszystko złoto, co się świeci (literally: Not all is gold that shines)
Chinese: 金玉其外，败絮其中 (Jīn yù qí wài, bài xù qí zhōng) (literally: Gold and jade outside, rotten cotton inside)