Dynamic URL vs Static URL

This situation often arises when communicating with network administrators: some widely held beliefs may have been true in the past, but they might no longer apply to the current context. Recently, we encountered such a scenario while discussing URL structures with a few friends. One friend was very concerned about the use of dynamic URLs and even thought that "search engines cannot handle dynamic URLs." Another friend felt that dynamic URLs posed no problem at all for search engines, as those issues were relics of the past. A third friend even admitted that he had never understood the difference between dynamic and static URLs. For us, this moment prompted us to thoroughly research the topic of dynamic and static URLs. First, let’s define what we are talking about:

What is a static URL?

A static URL, by definition, is one that does not change and usually does not contain any URL parameters. For example: http://www.example.com/archive/january.htm. You can search for static URLs on Google by entering filetype:html in the search box. Updating pages of this type can be time-consuming, especially when information grows rapidly, because each individual page must be recompiled. This is why webmasters use dynamic URLs when managing large, frequently updated websites like online shopping sites, forums, blogs, or content management systems.

What is a dynamic URL?

If a website's content is stored in a database and displayed upon request, then it uses dynamic URLs. In this case, the content provided by the site is generally based on templates. Typically, a dynamic URL looks like this: http://code.google.com/p/google-checkout-php-sample-code/issues/detail?id=31. You can identify dynamic URLs by looking for symbols like ? = &. One drawback of dynamic URLs is that different URLs can have the same content. This causes different users to link to URLs with different parameters, yet containing the same content. This is one reason why webmasters sometimes want to rewrite dynamic URLs into static ones.

Should I make my dynamic URLs appear static?

When dealing with dynamic URLs, there are a few facts you should be aware of:

- Correctly generating and maintaining the rewriting from dynamic URLs to static-like URLs is actually quite difficult.

- Providing us with the original dynamic URL is safer; let us handle issues like detecting and avoiding problematic parameters.

- If you choose to rewrite URLs, remove unnecessary parameters and keep them in their dynamic form.

If you want to provide a static URL instead of a dynamic one, you should genuinely generate corresponding static content.

Which one does Googlebot recognize better: static or dynamic URLs?

We have encountered many webmasters who, like our friends, believe that static or static-looking URLs give an advantage in indexing and ranking. This belief is based on the assumption that search engines have problems crawling and analyzing URLs containing session IDs and source trackers. However, the fact is that Google has made significant progress in these two areas. Static URLs may have a slight advantage in click-through rates because users can easily understand the URL. But regarding indexing and ranking, using a database-driven website does not mean a clear disadvantage. We prefer websites to directly provide dynamic URLs rather than hiding parameters to make them appear static.

Now, let's look at some widely spread views about dynamic URLs and correct some misconceptions that mislead webmasters. :)

Myth: "Dynamic URLs cannot be crawled."

Fact: We can crawl dynamic URLs and interpret different parameters. Hiding parameters that could provide valuable information to Google just to make the URL appear static can cause trouble for crawling and ranking. Our advice is: do not format a dynamic URL to make it look static. Using static URLs to display static content is desirable, but if you decide to present dynamic content, do not hide the parameters to make them appear static, as doing so would delete useful information that helps us analyze the URL.

Myth: "Dynamic URLs should have fewer than 3 parameters."

Fact: There is no limit on the number of parameters. However, a good rule of thumb is to avoid making your URLs too long (this applies to all URLs, whether static or dynamic). You can remove some parameters that are unimportant to Googlebot, giving users a cleaner dynamic URL. If you're unsure which parameters can be removed, we recommend providing all parameters in the dynamic URL, and our system will figure out which ones are unimportant. Hiding parameters can affect our ability to correctly analyze your URL, preventing us from identifying them and potentially losing important information.

Does this mean I should completely avoid rewriting dynamic URLs?

This is our recommendation unless you can ensure that you only remove redundant parameters or completely eliminate all parameters that could have adverse effects. If you arbitrarily modify your dynamic URLs to make them appear static, be aware that this carries risks, as it could lead to some information not being properly compiled and recognized. If you want to add a static version of your site, be sure to provide truly static content, such as files that can be accessed through the site's path. If you merely change the appearance of dynamic URLs without providing actual static content, you may achieve the opposite effect. It's best to provide us with standard dynamic URLs, and we will automatically find the redundant parameters.

Can you give me an example?

If you have a standard dynamic URL like foo?key1=value1&key2=value2, we suggest leaving it unchanged, allowing Google to decide which parameters can be removed; or you can remove unnecessary parameters for users, but do so cautiously, removing only unimportant parameters. Here is an example of a dynamic URL with multiple parameters:

www.example.com/article/bin/answer.foo?language=en&answer=3&sid=98971298178906&query=URL

- language=en – indicates the language of the article

- answer=3 – the article contains the number 3

- sid=98971298178906 – the session ID code is 98971298178906

- query=URL – the query that found this article is [URL]

Not all parameters provide additional information. Rewriting the URL as www.example.com/article/bin/answer.foo?language=en&answer=3 may not cause any problems since all unrelated parameters have been removed.

Here are some examples of manually modified URLs that appear static. Compared to providing dynamic URLs directly without rewriting, these URLs may cause more crawling problems.

- www.example.com/article/bin/answer.foo/en/3/98971298178906/URL

- www.example.com/article/bin/answer.foo/language=en/answer=3/sid=98971298178906/query=URL

- www.example.com/article/bin/answer.foo/language/en/answer/3/sid/98971298178906/query/URL

- www.example.com/article/bin/answer.foo/en,3,98971298178906,URL

If you rewrite dynamic URLs in the ways shown above, it may result in unnecessary crawling by us, as these URLs all contain variable values for session IDs (sid) and queries (query), which inadvertently generates many seemingly different URLs with the same content. These formats make it difficult for us to understand the actual content returned via the URL, as the parameters like URL and 98971298178906 are irrelevant. However, the following rewritten example removes all irrelevant parameters:

www.example.com/article/bin/answer.foo/en/3

Although we can correctly handle this URL, we do not encourage the use of such rewriting. It is difficult to maintain, and if a new parameter is added to the original dynamic URL, this URL needs to be updated immediately. Failing to do so could again result in a URL that hides parameters and appears static. Therefore, the best solution is usually to keep dynamic URLs in their original form. Alternatively, if you remove unrelated parameters, remember to keep the URL dynamic:

www.example.com/article/bin/answer.foo?language=en&answer=3

We hope this article helps you and our friends clarify the various speculations surrounding dynamic URLs. If you have more questions, feel free to join our [url=http://groups.google.com/group/google_webmaster_help-zh-CN] Webmaster Support Forum [/url] for discussion.