In general, however, search engines are text based. This means that in order to be crawled and indexed, your content needs to be in text format. (Google can now index text content contained in Flash files, but other search engines may not.)
This doesn't mean that you can't include rich media content such as Flash, Silverlight, or videos on your site; it just means that any content you embed in these files should also be available in text format or it won't be accessible to search engines. The examples below focus on the most common types of non-text content, but the guidelines are similar for any other types: Provide text equivalents for all non-text files.
This will not only increase Googlebot's ability to successfully crawl and index your content; it will also make your content more accessible. Many people, for example users with visual impairments, who use screen readers, or have low bandwidth connections, cannot see images on web pages, and providing text equivalents widens your audience.
We're continually working to improve our indexing of Flash files, but there are some limitations:
- We currently do not attach content from external resources that are loaded by your Flash files. If your Flash file loads another file—such as an HTML file, an XML file, or another SWF file—we may index the contents of those files, but we won't consider that content to be part of the content in your Flash files.
- We're currently unable to index the bidirectional language content (for example, Hebrew or Arabic) in Flash files.
You could also consider using sIFR (Scalable Inman Flash Replacement). sIFR (an open-source project) lets webmasters replace text elements with Flash equivalents. Using this technique, content and navigation is displayed by an embedded Flash object but, because the content is contained in the HTML source, it can be read by non-Flash users (including search engines).
|Silverlight and other rich media formats|
- Try to use rich media only where it is needed. We recommend that you use HTML for content and navigation. This makes your site more Google-friendly, and also makes it accessible to a larger audience including, for example, readers with visual impairments that require the use of screen readers, users of old or non-standard browsers, and users with limited or low-bandwidth connections such as a cellphone or mobile device. An added bonus? Using HTML for navigation will allow users to bookmark content and send direct links in email.
- Provide text versions of pages. Silverlight is often used as a splash screen on the home page, where the root URL of a website has a rich media intro that links to HTML content deeper into the site. If you use this approach on your website, make sure there is a regular HTML link on that front page to a text-based page where a user (or Googlebot) can navigate throughout your site without the need for rich media.