What does 'YMMV' stand for in online commentary?

“What does ‘YMMV’ stand for in online commentary?” — It stands for “Your mileage may vary.” The expression tells readers that an experience, result, or opinion may differ from person to person.

The phrase began as a disclaimer connected with American automobile advertising. Fuel-economy figures were estimates, so a vehicle’s actual mileage could vary with driving habits, traffic, weather, terrain, and maintenance. It later became a general-purpose idiom and was shortened to YMMV in online communication.

In forums, reviews, and social media, YMMV usually softens a recommendation: one person may have had excellent results with a product or method, while another may not. It is therefore close in meaning to “your experience may be different” or “this is only my perspective.”

A common mix-up is “your mileage might vary.” That wording conveys a similar idea in ordinary English, but it is not the standard expansion of the initialism. YMMV is also not a claim about literal fuel consumption when used in online commentary.