If it sounds too good to be true, it is.

This proverb-like warning is commonly used in consumer, financial, and fraud-prevention contexts to encourage skepticism toward offers that promise unusually high rewards for little cost or risk. It circulates widely in modern English as a piece of practical folk wisdom rather than a literary quotation with a single traceable author. The saying is frequently invoked in discussions of scams, get-rich-quick schemes, misleading advertising, and too-perfect narratives, functioning as a heuristic for everyday decision-making. Because it is anonymous and widely repeated, it is best understood as part of late-20th- and 21st-century popular advice culture rather than a line with a fixed original occasion.

The line expresses a rule of thumb: extraordinary claims and unusually favorable deals should trigger heightened scrutiny. It does not assert that good outcomes are impossible, but that improbably perfect promises often conceal hidden costs, omitted conditions, or deception. As a piece of folk logic, it appeals to probability and experience—most real opportunities involve tradeoffs, effort, or risk—so an offer that seems to violate those patterns is suspect. The quote’s enduring value lies in its simplicity: it compresses a cautious, evidence-seeking mindset into a memorable test for plausibility, especially useful when emotions like greed, hope, or urgency can override judgment.

1) "If it seems too good to be true, it probably is."
2) "If something sounds too good to be true, it probably is."
3) "When something sounds too good to be true, it usually is."