To downgrade can refer to several things. To 'dumb down', or to reduce in complexity, to remove unnecessary parts, or to reduce the number of moving parts/applications/stocks. The term downgrade is often used in the stock market to refer to a analyst’s change in the security of a stock, usually a negative change (e.g. from ‘buy’ to ‘sell’.)

Downgrading in meteorological terms refers to official reduction in a storms intensity. In computer software, downgrading refers to reverting software back to an older version. Often, complex programs may need to be downgraded to remove unused or bugged features, and to increase speed and/or ease of use. The same can occur with machinery. Downgrading is a common practice during wartime, when money and materials are in short supply. A good example of a downgraded wartime machine is the German steam locomotive Kregslok ("war loco"). Cash and materials were in short supply, and locomotives were needed to quickly supply troops and bases on the front lines, as well as to manage newly won territories. The German solution to this new and urgent demand for locomotives was the Kregslok, a steam locomotive that was downgraded greatly so that it consumed the cheapest metals and could be built by unskilled slave labor, thus helping the war effort.

An example of a downgraded program is Gmax, a downgraded version of 3ds max used by professional computer graphics artists, simplified for ease of use.

Downgrade is the opposite of upgrade.