Launching a new website is not a task to be taken lightly. Even in the most experienced of hands, there are a million and one things that can go wrong during the process, not least ballsing-up the SEO.

I’ve had the following conversation more than once:

“My company has just launched a new website.”

“Congratulations, you must be very happy.”

“No, not really, because now I can’t find us in Google and our traffic has dried up.”

“Did you redirect the old urls.”

“Redi-what?”

It’s very easy for me to assume that everyone who goes through the process of launching a new website places SEO pretty high on the do-not-balls-up list. The reality is, not everyone does, which can have some seriously negative implications on a business’ performance online, if only short-term.

Here are 5 things to consider when launching a new website, from an SEO point of view.

1) Redirects

If you’ve simply given your site a fresh lick of paint, maybe tweaked some copy and moved a few images around then you probably needn’t worry. But the chances are that if your newly designed site has some new pages and a new folder structure, then it also has a bunch of new urls.

This means that any old urls won’t work anymore, and anyone wishing to visit pages on those urls will be disappointed when they’re greeted with a 404 page. Furthermore, any links (internal or external) pointing to those 404 pages won’t be a lot of use to anyone.

So you need to permanently redirect those old urls to the new urls, via a 301 redirect. This tells Google that the page has moved, and also ensures your visitors end up in the right place.

2) Update links

Redirects implemented, you’ll also want to go ahead and update any links pointing to old urls, to point to the new ones.

Do this in as many places as you can. If you have any particularly valuable links from external domains, go ahead and ask them nicely to update the link to point to the new url.

Remember to update links across all of your other marketing collateral too: PPC, display, social etc.

3) Check for duplicate content

Duplicate content issues arise when a single page is available on more than one url, such as when a product is available via multiple categories on an e-commerce site. Other common examples include: uppercase urls changing to lowercase, or visa versa; dropping or adding the www.; adding or removing trailing slashes; .html or .aspx extensions etc.

Google doesn’t like duplicate content in its search results, so you’ll need to tell it which of your duplicated pages is the ‘master’, and ultimately which version should be shown in SERPs.

This can be achieved through the use of a canonical tag – more about that here.

4) Tracking codes

Remember to install any tracking codes (Google analytics, AdWords conversion codes etc.) on all of your new pages before the old site is switched off. Test this is all working before going live.

Whilst on the subject of Google Analytics, remember to update your goal urls where necessary.

5) Sitemaps

New site = new sitemap. Make sure you keep Google in the loop by submitting your sitemap via Webmaster Tools. Also check that your Robots.txt file is as it should be, and not blocking spiders from important areas of your site.

Whilst no means an exhaustive list, the points highlighted here should all be on your pre-launch checklist. For a broader overview of things to consider, I’d recommend reading Website Launch Checklist: 25 Things to Test Before Your Site Goes Live.