changing wordpress theme affects SEO?

It sounds like the cause is the change of the theme...

Did this effect your Titles and other SEO factors on your site?

Maybe you should try to change it back and see if there is any change.

It does not. Unless you change the structure of the permanent link

Your theme definitely affects the search engine effectiveness of your site. Here's an article I wrote on how and why it does:

http://www.wealthydragon.com/blog/20...earch-results/

I'd suggest restoring your theme to a copy backed up prior to the customisations.

Cheers,

Martin.

Thanks for all your help, I have rolled back to my old theme. Shame really as the new theme looked great and matched my site exactly.

The elancer was very defensive when I asked him about it, he had great feedback and claimed to have built over 2000 themes and was adamant it was my fault as I hadn’t enabled the google analytics on the blog. Although I can’t see how that would affect my site rankings, or the rest of my site! Fingers crossed my site will start showing up again, have had a week of missed sales!

Absolutely... Of course changing your theme can change your rankings. ANYTHING you do on your site can affect rankings. Massive changes to your template/theme can definitely affect it.

The new theme could be constructing your title elements differently. The new theme might be showing the entire post on the home/category/archives/tags pages creating a ton of duplicate content issues where the old one may have displayed a custom excerpt. The new one may be allowing the category/archives/tags pages to all be indexed again creating duplicate content where the old one might have noindexed the archives and tags pages. The new one may be using different fields from the CMS to generate link text. The new theme could be rendering the pages using a different URL structure and didn't 301 redirect old URLs to the new URLs.

There are literally thousands of things that the new theme could be doing or not doing that the old them did not or did do that could be affecting rankings.

AND to make things worse... since Caffeine and Mayday, I have seen MANY reports that massive changes to the template of your site (basically, any redesign of the site) are often having a big negative impact on rankings and taking MUCH longer to recover from a ranking perspective. Before when you'd do a site redesign you would expect a few weeks, maybe a month or two for Google to absorb all of the changes and for rankings and traffic to recover. But it seems lately that redesigns are throwing Google's algo into much more of a state of shock and it's taking several months now to recover from what used to take a few weeks.

If the new theme was well written from an SEO perspective, I would probably have just ridden it out, continuing to build links to the site... and wait for the rankings to return. But ONLY if after looking at the theme I determined from an SEO and user perspective that the new one was better.

That's a new on me. I didn't think it mattered as long as Google still indexed the same HTML markup. I'm guessing the new theme added a sidebar or whatever and that's what flagged it up by Google. I'm pretty sure if you only made changes to the theme on the CSS side you would have been ok.

However, if you change your title and heading tags or moved them elsewhere then yes it would have affected it.

I think it can. Some themes are SE-friendly: their structure makes it easy for search engines to find the content, etc. so... in your case maybe you switch from a SE-friendly theme to a less SE-friendly theme.

Otherwise make sure your permalinks are still there, as well as your page titles, etc.

Ya if your theme loads slower and has a lot of errors in its css then it would affect the PR.

Yes, I believe it does have a temporary negative effect on SE Ranking. But unless you picked a bad theme (ie. poorly coded etc.) then it's likely to find its way back up the SERPs again. If you got it to a decent level once, i'm sure you can get it up there again.

Like others have suggested, might be worth rolling back, but i have doubts that will make any immediate difference.

If the new theme you chose was because it was more SE Friendly, it might be worth giving your site a chance to move up the rankings again. You never know, you may even get it up to the number 1 position for your desired keywords if you give it some time.

In the mean time, throw some more link juice at it and make sure your new theme hasn't negatively impacted any of your on-page optimization!