In macroeconomics, crawling peg is an exchange rate regime that allows currency depreciation or appreciation to happen gradually. It is usually seen as a part of a fixed exchange rate regime.
The system is a method to fully use the key attributes of the fixed exchange regimes, as well as the flexibility of the floating exchange rate regime. The system is shaped to peg at a certain value, but at the same time is designed to "glide" to respond to external market uncertainties.