Bing Webmaster Tools:

• Total incoming links over time (currently the previous three weeks)
• Total incoming links to each page on the site (up to a maximum of 20,000 pages on the site)
• List of incoming links and corresponding anchor text (up to a maximum of 20,000 incoming links)

Google Webmaster Tools:

• Total incoming links
• List of most linked pages on the site
• List of domains that link most to the site
• Top anchor text
• Internal links

Of course, third-party link data also exists, including from Blekko, SEOmoz, and Majestic SEO. In the case of these tools, as well as Yahoo Site Explorer, the information is available for all sites, not just owner-verified ones. These are described a bit more in:

• Blekko’s SEO Tools: What Information Do They Provide?
• Yahoo Site Explorer: What’s The Status of the Link Data?
• All New Microsoft Bing Webmaster Tools (including comparison data between third party tools)
• Stuck in Link Limbo? How to Craft Real Business Metrics for Link Building

Bing Webmaster Tools Inbound Link Reports

Bing now provides information on incoming links to your site.  These new reports are easy to miss, but to find them, access a verified site, click the Index tab, then choose Links in the left navigation. If you have Silverlight installed, you’ll then see a graph that charts the number of incoming links to the site over time. As of today (December 19, 2010), the chart shows November 24 – December 16, 2010. You can hover over any point in time to see the exact count on that day.

The user interface of the chart clearly shows whether your incoming links have gone up or down, but it’s more difficult to tie that back to numbers, since that requires hovering. In the example above, the chart begins with 1,845,542 incoming links and ends with 2,220,551, with a high 2,306,928 on December 11th. Unfortunately, the total number of incoming links to your site over time isn’t available as a CSV export.

Below the chart, you can see a list of pages on the site and the number of incoming links to each. Since the first URL in the example above shows a count of > 250,000, I assume this is the cutoff for showing individual counts. You can click on any URL to see up to 20,000 (non-unique) source pages listed, along with anchor text used for those links.

Export Options

Perhaps because the UI is in Silverlight, it’s difficult to navigate through. The URLs listed in each case are in small frames that have both scroll bars and pagination. Fortunately, you can export both the link counts and incoming links as CSV files. Three export options exist.

• Inbound Links Export button – This exports the list of target pages on your site with incoming links (up to a maximum of 20,000) and the link count for each.
• URL Details Export button – This exports the list if source pages ((up to a maximum of 20,000)) that link to a particular page and the corresponding anchor text.
• Inbound Links Export All button – This exports a combined report of both of the above (up to a maximum of 1 million target URLs) in the format of Target Page | Source URL | Anchor Text.

How complete is the data? The Bing blog post says “it is important to note that the count of inbound links will be based on content stored in the Bing index vs. a complete, comprehensive count of links between every page on the Internet.” So presumably, the data accounts for all the links Bing knows about.

Google Webmaster Tools Link Reports

Google has made significant changes to the link data they provide since the original launch back in 2007. After providing a download of all links to up to a million pages on your site, that’s been scaled back to a maximum of 1,000. On the plus side, the current reports provide more insight than the original ones. The information currently provided is:

• Total number of incoming links
• The number of links to the most linked pages of the site – This report shows up  to 1,000 pages of the site and includes the number of links to the page and the number of source domains linking to it
• The domains that link to the site most often – This report shows up to 1,000 domains that link to the site and the number of times the domain links to individual URLs
• The most often used anchor text to the site
• The internal links to the site (including functionality to search for a specific page on the site to see internal links to it)

Much of this data is available as a download (although the ability to download it at once from all verified sites is no longer available). As with Bing, the total number of incoming links is available only in the UI and not as a download. Also, this data is unfortunately not available as part of the API. If you click further into the UI, you can also see more granular data. Both the data available for download and the granular data are described in Export Options, below.

Functionality and data that is no longer provided includes a list of all URLs on a site that have incoming links and the ability to search for a particular URL on the site to see incoming links to it. This list of URLs with corresponding incoming links used to be available as a download as well (up to a maximum of 1 million). Now, you can download a list of up to a million incoming links, but these aren’t associated with the pages they link to.

One other potential shortcoming of the Google data is that it appears to count links from subdomains as external links. In previous incarnations of this data, you could filter out data from subdomains, but that doesn’t seem to be available anymore. You can, of course, download the data to do this, but since the data that’s downloadable is limited, you can’t use this method to get a true picture of the total number of external links to the site. You can sort of approximate this by finding your domain in the “who links the most” reporting and subtracting that number from the total.

Export Options

From any page of the interface, you can click Download all links to get a All_Links report that provides a list of up to a million incoming links to the site. In addition, you can download the following:

• Who links the most > Download this table – provides a LinkingDomains report that lists:
  • number of incoming links from each domain (for up to 1,000 domains)
  • number of pages that domain links to

Unfortunately, this CSV file doesn’t provide a list of pages linked to. To get that, you have to download data for each domain separately as described below.

• Who links the most > (expand a domain> More > Download this table – provides a PagesLinkedFrom report that lists:
  • the pages of the site that domain links to (for up to 1,000 pages)
  • The number of links to each page

Want to see the pages on each domain that contain these links? For that, you’ll have to click even further.

• Who links the most > (expand a domain) > More > (click a URL) > Download this table – provides a Links_from report that lists:
  • The pages on the domain that link to the specific page on your site (along with the redirect chain (called “intermediate links”), if applicable)
• Your most linked content > Download this table – provides a LinkedPages report that lists:
  • The pages on your site with the most links (for up to 1,000 pages)
  • The number of links to each page
  • The number of domains linking to each page

As with the linking domains data, to get granular information about specifically what domains link to the pages of your site, you’ll have to dig a bit deeper.

• Your most linked content > (expand a URL) > More > Download this table – provides a DomainsLinkingTo report that lists:
  • The list of domains linking to the page (for up to 1,000 domains)
  • The number of times each domain links to the page

You can’t drill in further to see what pages on each domain link to each of your pages.

• How your data is linked > Download this table – provides an AnchorPhrases report that lists the top  200 phrases used to link to the site.

Internal link data is also available to download.

• Internal links > Download this table – provides an InternalLinks report that lists:
  • The pages on the site with the most internal links (for up to 1,000 pages)
  • The number of internal links to each page

As with several of the other reports, you can click on an individual URL of the site to see the list of internal links to it.

• Internal links > (click a URL) > Download this table – provides an InternalLinks_to report that lists the internal pages of the site that link to the URL.

I know. Kind of exhausting, right? But good data to have.

What about the future of Yahoo Site Explorer data now that Bing powers Yahoo search results? As I noted in October, Yahoo is still crawling the web and providing link data as part of Site Explorer. They told me that “We are working with Microsoft to ensure that we will continue to have comprehensive, fresh link data for Yahoo! Site Explorer when we switch from Yahoo!’s data to Microsoft data in the future.”

How The Data Compares

How does Bing data compare to Google data? Below you’ll see the results of analysis I ran on a few sites. The Google number is the total count minus that number of links listed for that domain (to remove the counts from subdomains). In all but one case, Google lists significantly more links than Bing, although in a few cases, Google gave me no link data at all.

In the one case where Bing shows significantly more links to a site than Google does, the site has substantial subdomains (in fact, the original link count from Google was 138 million, 133 of which were subdomains of the site), which makes me wonder if Bing is, in fact, excluding all subdomain links from its counts.