The Internet has drastically altered the way in which information is shared, and has had a profound impact on marketing. Over the past few years, there has been more of a shift toward inbound techniques, while many outbound tactics have become antiquated. More businesses are finding success publishing original content rather than embedding advertisements within external content, because of the additional benefits these tactics offer, such as branding and audience growth.

If you are having depreciated HTML tags then you have to remove them for sure. Its not a tough task to do. Just little changes are required like changing a tag line or whatever the error is. And in SEO, if these changes can be resolved then it will be beneficial to some extent but not that much that it may affect your rankings. Its better to be error free rather then going with bugs all around you. You may never know what Google brings in with their Updates.

Deprecated html affects your site negatively because it creates a bad user experience for your visitors since sites using deprecated tags won't display properly on some browsers.

Thanks For The Input Guys

Ill get on to it today and make the amendments required

Cheers

Bertie

A lot depends on how common the tag is - most browsers keep displaying deprecated tags for some time - there are quite a few tags still in common use and still being rendered fine that were technically Netscape only and date back to when that was the dominant browser.

So it's almost certainly not an immediate problem.

But valid HTML is well worth using as browsers often tighten up how they render pages and that can (and does) break invalid HTML.

And also make sure that you test how your site displays in as many modern browsers as you can sensibly get hold of. On a Windows machine, I test in Chrome, Firefox, Internet Explorer and sometimes Safari. If it validates close to 100% and renders the same in all of those you're as safe as you're likely to be.

Look at the Google cache (text version), that will help show you what Google is looking at (onpage text/links).

Be careful editing old webpages that are already ranked. Removing other internal pages/links/text that helped rank a page can drop a page in the SERPs If Google finds links/pages missing on the next crawl.