Don’t judge a book by its cover
Definition 1 of 1
Pro Tip 1/3Beyond Appearances
Understand that this idiom stresses looking deeper than surface level, encouraging looking past the obvious. 
His clothes were old and worn, but don't judge a book by its cover, he's a successful entrepreneur.
Pro Tip 2/3Context Matters
Use this phrase in situations where there's a risk of quick judgments without enough information. 
The quiet student hardly speaks, but don't judge a book by its cover, she has brilliant ideas.
Pro Tip 3/3Misleading First Impressions
This idiom often hints at the unreliability of first impressions, urging a more thorough assessment. 
Their proposal seemed weak, but don't judge a book by its cover; the details reveal a solid plan.