One of the most important guidelines of onpage SEO (search-engine-optimization) and in order for your webpage to load faster is that you use CSS Image Sprites for your webpage's images.
This means that you do not insert a lot of images in your HTML code but combine them into one and you display them with proper CSS code.
By using CSS Sprites you reduce significantly the dns queries and file queries when your webpage is being loaded by just the one of your combined CSS Sprites image.
This results into faster loading times and search engines prefer webpages that load fast !
With CSS Sprites Generator from 4dots Software you can easily generate CSS Sprites with just a few mouse clicks !
This free tool will generate both the combined CSS Sprites image and the CSS, HTML code that is required.
You can also save your work as a project and open it later.
Free source code is also available.
It is different from competitors because it enables the user to save and load projects. It is also free and open-source. Moreover, it generates a CSS file and HTML file to test the result.