Implementations generally relate to optimizing bar charts. In some implementations, a method includes receiving a plurality of data points, where each data point of the plurality of data points has a value. The method further includes determining a plurality of bars of the bar chart based on the plurality of data points, where each bar of the plurality of bars has a length and a width. The method further includes associating a plurality of pixels used to render the bar chart with the plurality of bars. The method further includes determining for each pixel of the plurality of pixels at least one or more of a highest positive bar and a lowest negative bar. The method further includes rendering for each pixel one or more of the respective highest positive bar and the respective lowest negative bar.