chartd makes it easy to include charts (either png or svg) on your web site, by just passing parameters in the URL of an img tag. For simple charts, this will be easy-peasy to automate. Of course, the downside is the same as for any other time that you let a third-party service have responsibility for your content — what if they shut down the service? 

chartd – responsive, retina-compatible charts with just an img tag