An organic light emitting display device includes a plurality of pixels in a display area; a data driver configured to supply a data signal to the pixels; and a data converter configured to output a correction image data utilized in generation of the data signal, and the data converter is configured to generate a stress data corresponding to an input image data, to accumulate and store at least a portion of the stress data in a compressed state, and to generate the correction image data obtained by correcting the input image data according to the accumulated stress data.