Don't judge a book by its cover.
“Don't judge a book by its cover.”
Do not form an opinion about someone or something based only on outward appearance.
— Traditional United Kingdom Wisdom, United Kingdom
Source: Traditional English-language proverb, widely attested in English usage since the mid-20th century
More Proverbs from United Kingdom
A stitch in time saves nine.
Dealing with a small problem promptly prevents it from becoming a much bigger one.
Don't count your chickens before they hatch.
Do not rely on something good happening before it has actually happened.
The early bird catches the worm.
Those who act promptly or arrive first gain an advantage.
Too many cooks spoil the broth.
When too many people work on a single task, the result is worse, not better.
Every cloud has a silver lining.
Even in difficult situations there is usually some hope or positive aspect.
When in Rome, do as the Romans do.
Adapt to the customs of the place or company you find yourself in.