HTML / XML / JS, low-level validity (cross-cutting)LowInferred
Deprecated HTML elements
Deprecated elements like font, center or marquee may render inconsistently and signal dated, unmaintained markup. Modern semantic HTML and CSS are the replacement.
What it is
font/center etc.
Why it matters
Dated, non-semantic markup.
How to fix it
Use modern semantic HTML + CSS.
How to find it on your site
- Scan the markup for deprecated elements and attributes.
- Replace them with current semantic elements and CSS.
- Re-validate against the current HTML spec.
- Standardise on modern markup going forward.
Cross-reference to ranking and citation factors
Deprecated elements are unreliable and signal neglected code. Modern markup is more robust and maintainable.
Impact
Low. Inferred.
Evidence
Semantic HTML is recommended. Google Search Central, Understand JavaScript SEO Basics