Methods, apparatus, systems and articles of manufacture to perform quantization offset and/or cost factor modification for video encoding are disclosed. Some example methods for video encoding disclosed herein include adjusting a quantization offset to quantize a transform coefficient representative of a pixel block in a frame of a video sequence. For example, the quantization offset can be adjusted based on a quantization parameter obtained to quantize the transform coefficient. Some such example methods also include quantizing the transform coefficient according to the quantization parameter and the quantization offset. Some example methods for video encoding disclosed herein additionally or alternatively include adjusting a cost factor based on a characteristic of a pixel block in a frame of a video sequence. Some such example methods also include determining, based on the cost factor, a cost associated with encoding the pixel block according to a first encoding mode.