An organic light emitting display device includes a display panel including and a plurality of pixels, a gate driver configured to a normal gate signal and an alternative gate signal to the pixels, a data driver configured to provide a data signal to the pixels, an emission control driver configured to an emission control signal to the pixels, and a controller configured to control the gate driver, the data driver, and the emission control driver. Each of the pixels is driven by the normal gate signal in a first driving mode and is driven by the alternative gate signal in a second driving mode. A threshold voltage of a first transistor is compensated in the first driving mode and the threshold voltage of the first transistor is not compensated in the second driving mode.