Front-end
Front-end auditing is about understanding how the website code is optimized from a performance perspective. It goes hand-in-hand with Page Speed auditing, which is why both are selected with Sitebulb when you set up an audit.
Where Sitebulb's Page Speed Hints focus on optimization of the server, caching and the critical path, the Front-end Hints examine issues in the code itself, providing CSS & HTML validation and checking for JavaScript errors (and additionally collecting cookies).
Front-end is much more 'developer-led' than 'SEO-led', whereas Page Speed has tended to skirt the two, the Hints you will find in this section relate to performance improvements that can be gained by fixing HTML and CSS issues.
Front-end Issues
All bar one of the Front-end Hints are Issues (one Insight, at the bottom), which means they represent errors or problems that need to be fixed. They are additionally classified in terms of their importance - this should be taken into account when prioritizing implementation work, along with the number and type of URLs affected.
Importance: Critical
These Hints require immediate attention, as the issue may have a serious impact upon crawling, indexing or ranking.
Importance: High
These Hints are very important, and definitely warrant attention.
- CSS content has errors
- CSS contains duplicate background images
- Contains duplicate element id values
- Does not contain any HTML when JavaScript is turned off
- Contains a broken tag
- Contains an attribute with an unsafe character
- Contains an attribute whose value is not enclosed in double quotes
Importance: Medium
These Hints are worth investigating further, and may warrant further attention depending on the type and quantity of URLs affected.
- Logs messages in the browser's console
- Missing <noscript> tag in the <body>
- CSS contains overqualified selectors
- CSS content contains duplicate CSS properties
- CSS contains @import
- Contains an un-encoded special character
Importance: Low
These Hints are of the lowest significance, and should only be addressed if there aren't more serious issues which have not been handled.
- Document compatibility mode meta position invalid
- Document compatibility mode in <head> and headers differ
- CSS content empty rules
- CSS content contains unknown CSS properties
- CSS contains zero unit declarations
- CSS contains universal selector
- CSS contains unqualified attributes
- Contains a duplicate attribute
Front-end Insights
Insights are neither issues nor opportunities, and often don't require any action at all - they are brought to your attention as they may provide a useful avenue of investigation.