Redesign with SEO in mind

Can you understand the page content without the visual cues humans are used to processing? Try outlining headings. Does anything stand out as more prominent? Do those headings use unique, relevant, popular keywords? Or do they all say “More Info”?

If you can't understand the site when surfing in this way, it's likely that the natural search performance will be seriously limited as well.

Free crawlers are another excellent tool for testing how crawlable a site is, and how many URLs are generated unintentionally. Crawlers such as GSite Crawler (http://gsitecrawler.com) and Link Sleuth (http://home.snafu.de/tilman/xenulink.html#Description) catalog URLs as they crawl and generate an exported list that can be sorted and filtered to identify duplicate URLs and title tags, among other things.

I typically start by sorting the URLs alphabetically in Excel and looking for appended parameters I didn't expect. Then I might choose a product or category number or identifying keyword and filter by that to determine if different URL structures represent the same product or category.

I'll also sort the title tags alphabetically and filter on identifying keywords to identify duplication. Fixing the sources of duplication in development is far easier than weeding them out when they're live and indexed.

If the structure of the site is strong, content optimization and external link building can all be strengthened after launch. But if the structure is weak or the templates and platform don't allow for optimization at launch, resolving it post-launch represents a much bigger challenge.

Create 301 maps to pass SEO strength to the new site

When a site is stable on the development environment and the URLs are ironed out, identify a 301 redirect plan. The basic principle is simple: For SEO and user experience both, redirects should be put in place for every legacy URL, redirecting them to the new URLs. For example:

• http://www.domain.com/pub/article1.html → 301 redirect → http://www.domain.com/keyword/new-article-url.html.

Many servers default to 302 temporary redirects. As small as the difference seems, the redirects must be 301 permanent redirects. Only 301 redirects pass the legacy URL's link popularity to the new URL and prompt the engines to de-index the legacy URL. A 302 redirect merely moves the user agent to the new URL, without passing link popularity or prompting de-indexation.

The tricky part comes in identifying the universe of legacy URLs to 301 redirect. It's not enough to 301 the URLs you know exist; you really need to clean house and identify those forgotten pockets of duplicate or forgotten pages littering the server.

To find these URLs, comb through the major engines' indexes using combined search operators such as site: and inurl: queries to determine what's indexed. For a large site, crawling the existing live site using the crawlers mentioned above will be much more effective and efficient, though it may take many hours to complete.

You can also examine log files to identify which URLs have been served, but URLs lurking in dark corners may not appear in recent log files. A combination of all these approaches will yield significant overlap, but also the most complete final list. Dump all of the legacy URLs into a single Excel spreadsheet and pair each one with the new URL that contains the same — or most similar — content.

Ideally, every known legacy URL would have a 301 redirect to a new URL. This can be done with pattern matching if the URLs follow predictable patterns. If not, thousands of individual 301 redirects are not likely to be practical.

Determine which URLs have the most link popularity to pass to the new URLs. Harvesting legacy link popularity to boost the performance of the new site is the primary SEO purpose of 301 redirects.

For those not able to 301 redirect, a hard 404 error should be returned. The 404 will also prompt de-indexation, and can be modified to load a custom, friendly error page. Ensure that the server header returned is a 404, though, or de-indexation of legacy URLs will not occur.

Measure the transition

It can take 30 to 90 days after a redesign or replatform before the site stabilizes and begins performing predictably. Whether this transition time is 30 days or 90 days depends on the strength of your current SEO, the cleanness with which the transition is executed, and the strength of the new site's SEO.

To measure the transition, track crawling (log files, Google Webmaster Tools), indexation (major engine site: queries), rankings (major engines, or ranking tools), traffic and conversions (Web analytics) weekly until the trend line stabilizes. Wherever it stabilizes is the new baseline to measure ongoing SEO efforts.

Give the transition trend lines time to stabilize before applying additional optimization. Layering change upon change can result in a muddy mess where cause and effect become impossible to measure.

Redesigning or replatforming a site is a complex process that requires a lot of planning and a lot of testing. But if you're included in the design process and armed with the SEO mantras, a strong testing plan, and a 301 map, you can minimize SEO performance issues during the transition.

Jill Kocher (jill@netconcepts.com) is manager of natural search consulting at search marketing firm Netconcepts.

Online resource guide

For details about performing a 60-second Website audit, visit http://www.naturalsearchblog.com/archives/2009/06/19/60-second-website-audit/

For more on progressive enhancement, visit http://en.wikipedia.org/wiki/Progressive_enhancement

To find Chris Pederick's Web Developer Toolbar add-on, visit http://chrispederick.com/work/web-developer/

To brush up on search operators, visit http://www.google.com/help/cheatsheet.html