They rate or score or grade your website based on the following major aspects:
- Metadata – Page title, Description, Keywords etc.
- Image Summary – Checks the loading time
- Readability Level – One of interesting aspect
- Google Page Rank, Google Indexed Pages
- Alexa Traffic Rank
- Directory Listings
- Blog Analysis and Ranking – If Blog
- Bookmarking Submissions mainly Digg.com and del.icio.us
- Competitive Intelligence
And you can even grab some cool badges to display your website score or grade in your website.
HubSpot, the inventor of Website Grader, even offers a free kit of marketing tips about how to improve your website. Download their Free Internet Marketing Kit Now.