The Google Chart API returns a PNG-format image in response to a URL. Several types of image can be generated: line, bar, and pie charts for example. For each image type you can specify attributes such as size, colors, and labels. And best of all its absolutely free!
You can include a Chart API image in a webpage by embedding a URL within an
<img> tag. When the webpage is displayed in a browser the Chart API renders the image within the page.
Types of charts are Line chart, Bar chart, Pie chart, Venn diagram, Scatter plot. For more details and how to use the Google Chart API, check out the developerÃ¢â‚¬â„¢s guide of Google Chart API.