Better safe than sorry
Definition 1 of 1
Pro Tip 1/3Risk Avoidance
The phrase emphasizes preventing problems, suggesting it's wise to avoid risks when possible. 
She brought an umbrella despite the sunny morning, thinking better safe than sorry.
Pro Tip 2/3Not Literal
This phrase is not usually about physical safety, but about being cautious to prevent any trouble. 
They backed up their computer files, preferring to be better safe than sorry.
Pro Tip 3/3No Regrets
Using this phrase indicates you'd rather do something unnecessary than regret doing nothing. 
I'll take a sweater along with me, better safe than sorry.