Google uses a wide range of IP addresses for its different services, and the addresses may change without notification. Google App Engine is a Platform as a Service offering which hosts a wide variety of 3rd party applications. This post announces changes in the IP address range and headers used by the Google App Engine URLFetch (outbound HTTP) and outbound sockets APIs.

While we recommend that App Engine IP ranges not be used to filter inbound requests, we are aware that some services have created filters that rely on specific addresses. Google App Engine will be changing its IP range beginning this month. Please see these instructions to determine App Engine’s IP range.

Additionally, the HTTP User-Agent header string that historically allowed identification of individual App Engine applications should no longer be relied on to identify the application. With the introduction of outbound sockets for App Engine, applications may now make HTTP requests without using the URLFetch API, and those requests may set a User-Agent of their own choosing.

Posted by the Google App Engine Team

Webmaster level: all

When music lovers search for their favorite band on Google, we often show them a Knowledge Graph panel with lots of information about the band, including the band’s upcoming concert schedule. It’s important to fans and artists alike that this schedule be accurate and complete. That’s why we’re trying a new approach to concert listings. In our new approach, all concert information for an artist comes directly from that artist’s official website when they add structured data markup.

If you’re the webmaster for a musical artist’s official website, you have several choices for how to participate:

1. You can implement schema.org markup on your site. That’s easier than ever, since we’re supporting the new JSON-LD format (alongside RDFa and microdata) for this feature.
2. Even easier, you can install an events widget that has structured data markup built in, such as Bandsintown, BandPage, ReverbNation, Songkick, or GigPress.
3. You can label the site’s events with your mouse using Google’s point-and-click webmaster tool: Data Highlighter.

All these options are explained in detail in our Help Center. If you have any questions, feel free to ask in our Webmaster Help forums. So don’t you worry `bout a schema.org/Thing … just mark up your site’s events and let the good schema.org/Times roll!

Posted by Justin Boyan, Product Manager, Google Search

Webmaster Level: Advanced

Faceted navigation, such as filtering by color or price range, can be helpful for your visitors, but it’s often not search-friendly since it creates many combinations of URLs with duplicative content. With duplicative URLs, search engines may not crawl new or updated unique content as quickly, and/or they may not index a page accurately because indexing signals are diluted between the duplicate versions. To reduce these issues and help faceted navigation sites become as search-friendly as possible, we’d like to:

• Provide background and potential issues with faceted navigation
• Highlight worst practices
• Share best practices
  • New faceted navigation implementations or redesigns
  • Existing faceted navigation implementations

Selecting filters with faceted navigation can cause many URL combinations, such as http://www.example.com/category.php?category=gummy-candies&price=5-10&price=over-10

Background

In an ideal state, unique content — whether an individual product/article or a category of products/articles —  would have only one accessible URL. This URL would have a clear click path, or route to the content from within the site, accessible by clicking from the homepage or a category page.

Ideal for searchers and Google Search

• Clear path that reaches all individual product/article pages
  
  On the left is potential user navigation on the site (i.e., the click path), on the right are the pages accessed.

• One representative URL for category page
  http://www.example.com/category.php?category=gummy-candies
  
  Category page for gummy candies

• One representative URL for individual product page
  http://www.example.com/product.php?item=swedish-fish
  
  Product page for swedish fish

Undesirable duplication caused with faceted navigation

• Numerous URLs for the same article/product

  Canonical	Duplicate
  example.com/product.php? item=swedish-fish	example.com/product.php? item=swedish-fish&category=gummy-candies&price=5-10

  Same product page for swedish fish can be available on multiple URLs.

• Numerous category pages that provide little or no value to searchers and search engines)

  URL	example.com/category.php? category=gummy-candies&taste=sour&price=5-10	example.com/category.php? category=gummy-candies&taste=sour&price=over-10
  Issues	No added value to Google searchers given users rarely search for [sour gummy candy price five to ten dollars]. No added value for search engine crawlers that discover same item (“fruit salad”) from parent category pages (either “gummy candies” or “sour gummy candies”). Negative value to site owner who may have indexing signals diluted between numerous versions of the same category. Negative value to site owner with respect to serving bandwidth and losing crawler capacity to duplicative content rather than new or updated pages.	No value for search engines (should have 404 response code). Negative value to searchers.

Worst (search un-friendly) practices for faceted navigation

Worst practice #1: Non-standard URL encoding for parameters, like commas or brackets, instead of “key=value&” pairs.

Worst practices:

• example.com/category?[category:gummy-candy][sort:price-low-to-high][sid:789]
• key=value pairs marked with : rather than =
• multiple parameters appended with [ ] rather than &
• example.com/category?category,gummy-candy,,sort,lowtohigh,,sid,789
• key=value pairs marked with a , rather than =
• multiple parameters appended with ,, rather than &

Best practice:

example.com/category?category=gummy-candy&sort=low-to-high&sid=789

While humans may be able to decode odd URL parameters, such as “,,”, crawlers have difficulty interpreting URL parameters when they’re implemented in a non-standard fashion. Software engineer on Google’s Crawling Team, Mehmet Aktuna, says “Using non-standard encoding is just asking for trouble.” Instead, connect key=value pairs with an equal sign (=) and append multiple parameters with an ampersand (&).

Worst practice #2: Using directories or file paths rather than parameters to list values that don’t change page content.

Worst practice:

example.com/c123/s789/product?swedish-fish
(where /c123/ is a category, /s789/ is a sessionID that doesn’t change page content)

Good practice:

example.com/gummy-candy/product?item=swedish-fish&sid=789 (the directory, /gummy-candy/,changes the page content in a meaningful way)

Best practice:

example.com/product?item=swedish-fish&category=gummy-candy&sid=789 (URL parameters allow more flexibility for search engines to determine how to crawl efficiently)

It’s difficult for automated programs, like search engine crawlers, to differentiate useful values (e.g., “gummy-candy”) from the useless ones (e.g., “sessionID”) when values are placed directly in the path. On the other hand, URL parameters provide flexibility for search engines to quickly test and determine when a given value doesn’t require the crawler access all variations.

Common values that don’t change page content and should be listed as URL parameters include:

• Session IDs
• Tracking IDs
• Referrer IDs
• Timestamp

Worst practice #3: Converting user-generated values into (possibly infinite) URL parameters that are crawlable and indexable, but not useful in search results.

Worst practices (e.g., user-generated values like longitude/latitude or “days ago” as crawlable and indexable URLs):

• example.com/find-a-doctor?radius=15&latitude=40.7565068&longitude=-73.9668408

• example.com/article?category=health&days-ago=7

Best practices:

• example.com/find-a-doctor?city=san-francisco&neighborhood=soma

• example.com/articles?category=health&date=january-10-2014

Rather than allow user-generated values to create crawlable URLs  — which leads to infinite possibilities with very little value to searchers — perhaps publish category pages for the most popular values, then include additional information so the page provides more value than an ordinary search results page. Alternatively, consider placing user-generated values in a separate directory and then robots.txt disallow crawling of that directory.

• example.com/filtering/find-a-doctor?radius=15&latitude=40.7565068&longitude=-73.9668408
• example.com/filtering/articles?category=health&days-ago=7

with robots.txt:

User-agent: *
Disallow: /filtering/

Worst practice #4: Appending URL parameters without logic.

Worst practices:

• example.com/gummy-candy/lollipops/gummy-candy/gummy-candy/product?swedish-fish
• example.com/product?cat=gummy-candy&cat=lollipops&cat=gummy-candy&cat=gummy-candy&item=swedish-fish

Better practice:

example.com/gummy-candy/product?item=swedish-fish

Best practice:

example.com/product?item=swedish-fish&category=gummy-candy

Extraneous URL parameters only increase duplication, causing less efficient crawling and indexing. Therefore, consider stripping unnecessary URL parameters and performing your site’s “internal housekeeping”  before generating the URL. If many parameters are required for the user session, perhaps hide the information in a cookie rather than continually append values like cat=gummy-candy&cat=lollipops&cat=gummy-candy& …

Worst practice #5: Offering further refinement (filtering) when there are zero results.

Worst practice:

Allowing users to select filters when zero items exist for the refinement.

Refinement to a page with zero results (e.g., price=over-10) is allowed even though it frustrates users and causes unnecessary issues for search engines.

Best practice

Only create links/URLs when it’s a valid user-selection (items exist). With zero items, grey out filtering options. To further improve usability, consider adding item counts next to each filter.

Refinement to a page with zero results (e.g., price=over-10) isn’t allowed, preventing users from making an unnecessary click and search engine crawlers from accessing a non-useful page.

Prevent useless URLs and minimize the crawl space by only creating URLs when products exist. This helps users to stay engaged on your site (fewer clicks on the back button when no products exist), and helps minimize potential URLs known to crawlers. Furthermore, if a page isn’t just temporarily out-of-stock, but is unlikely to ever contain useful content, consider returning a 404 status code. With the 404 response, you can include a helpful message to users with more navigation options or a search box to find related products.

Best practices for new faceted navigation implementations or redesigns

New sites that are considering implementing faceted navigation have several options to optimize the “crawl space” (the totality of URLs on your site known to Googlebot) for unique content pages, reduce crawling of duplicative pages, and consolidate indexing signals.

• Determine which URL parameters are required for search engines to crawl every individual content page (i.e., determine what parameters are required to create at least one click-path to each item). Required parameters may include item-id, category-id, page, etc.
• Determine which parameters would be valuable to searchers and their queries, and which would likely only cause duplication with unnecessary crawling or indexing. In the candy store example, I may find the URL parameter “taste” to be valuable to searchers for queries like [sour gummy candies] which could show the result example.com/category.php?category=gummy-candies&taste=sour. However, I may consider the parameter “price” to only cause duplication, such as category=gummy-candies&taste=sour&price=over-10. Other common examples:
• Valuable parameters to searchers: item-id, category-id, name, brand…
• Unnecessary parameters: session-id, price-range…
• Consider implementing one of several configuration options for URLs that contain unnecessary parameters. Just make sure that the unnecessary URL parameters are never required in a crawler or user’s click path to reach each individual product!

  • Option 1: rel=”nofollow” internal links
    

    Make all unnecessary URLs links rel=“nofollow.” This option minimizes the crawler’s discovery of unnecessary URLs and therefore reduces the potentially explosive crawl space (URLs known to the crawler) that can occur with faceted navigation. rel=”nofollow” doesn’t prevent the unnecessary URLs from being crawled (only a robots.txt disallow prevents crawling). By allowing them to be crawled, however, you can consolidate indexing signals from the unnecessary URLs with a searcher-valuable URL by adding rel=”canonical” from the unnecessary URL to a superset URL (e.g. example.com/category.php?category=gummy-candies&taste=sour&price=5-10 can specify a rel=”canonical” to the superset sour gummy candies view-all page at example.com/category.php?category=gummy-candies&taste=sour&page=all).

  • Option 2: Robots.txt disallow
    

    For URLs with unnecessary parameters, include a /filtering/directory that will be robots.txt disallow’d. This lets all search engines freely crawl good content, but will prevent crawling of the unwanted URLs. For instance, if my valuable parameters were item, category, and taste, and my unnecessary parameters were session-id and price. I may have the URL:
    example.com/category.php?category=gummy-candies
    which could link to another URL valuable parameter such as taste:
    example.com/category.php?category=gummy-candies&taste=sour.
    but for the unnecessary parameters, such as price, the URL includes a predefined directory, /filtering/:
    example.com/filtering/category.php?category=gummy-candies&price=5-10
    which is then robots.txt disallowed

    User-agent: *
Disallow: /filtering/

  • Option 3: Separate hosts
    

    If you’re not using a CDN (sites using CDNs don’t have this flexibility easily available in Webmaster Tools), consider placing any URLs with unnecessary parameters on a separate host — for example, creating main host www.example.com and secondary host, www2.example.com. On the secondary host (www2), set the Crawl rate in Webmaster Tools to “low” while keeping the main host’s crawl rate as high as possible. This would allow for more full crawling of the main host URLs and reduces Googlebot’s focus on your unnecessary URLs.

    • Be sure there remains at least one click path to all items on the main host.
    • If you’d like to consolidate indexing signals, consider adding rel=”canonical” from the secondary host to a superset URL on the main host (e.g. www2.example.com/category.php?category=gummy-candies&taste=sour&price=5-10 may specify a rel=”canonical” to the superset “sour gummy candies” view-all page, www.example.com/category.php?category=gummy-candies&taste=sour&page=all).

• Prevent clickable links when no products exist for the category/filter.
• Add logic to the display of URL parameters.
• Remove unnecessary parameters rather than continuously append values.
• Avoid
  example.com/product?cat=gummy-candy&cat=lollipops&cat=gummy-candy&item=swedish-fish)
• Help the searcher experience by keeping a consistent parameter order based on searcher-valuable parameters listed first (as the URL may be visible in search results) and searcher-irrelevant parameters last (e.g., session ID).
• Avoid
  example.com/category.php?session-id=123&tracking-id=456&category=gummy-candies&taste=sour
• Improve indexing of individual content pages with rel=”canonical” to the preferred version of a page. rel=”canonical” can be used across hostnames or domains.
• Improve indexing of paginated content (such as page=1 and page=2 of the category “gummy candies”) by either:
• Adding rel=”canonical” from individual component pages in the series to the category’s “view-all” page (e.g. page=1, page=2, and page=3 of “gummy candies” with rel=”canonical” to category=gummy-candies&page=all) while making sure that it’s still a good searcher experience (e.g., the page loads quickly).
• Using pagination markup with rel=”next” and rel=”prev” to consolidate indexing properties, such as links, from the component pages/URLs to the series as a whole.
• Be sure that if using JavaScript to dynamically sort/filter/hide content without updating the URL, there still exists URLs on your site that searchers would find valuable, such as main category and product pages that can be crawled and indexed. For instance, avoid using only the homepage (i.e., one URL) for your entire site with JavaScript to dynamically change content with user navigation —  this would unfortunately provide searchers with only one URL to reach all of your content. Also, check that performance isn’t negatively affected with dynamic filtering, as this could undermine the user experience.
• Include only canonical URLs in Sitemaps.

Best practices for existing sites with faceted navigation

First, know that the best practices listed above (e.g., rel=”nofollow” for unnecessary URLs) still apply if/when you’re able to implement a larger redesign. Otherwise, with existing faceted navigation, it’s likely that a large crawl space was already discovered by search engines. Therefore, focus on reducing further growth of unnecessary pages crawled by Googlebot and consolidating indexing signals.

• Use parameters (when possible) with standard encoding and key=value pairs.
• Verify that values that don’t change page content, such as session IDs, are implemented as standard key=value pairs, not directories
• Prevent clickable anchors when products exist for the category/filter (i.e., don’t allow clicks or URLs to be created when no items exist for the filter)
• Add logic to the display of URL parameters
• Remove unnecessary parameters rather than continuously append values (e.g., avoid example.com/product?cat=gummy-candy&cat=lollipops&cat=gummy-candy&item=swedish-fish)
• Help the searcher experience by keeping a consistent parameter order based on searcher-valuable parameters listed first (as the URL may be visible in search results) and searcher-irrelevant parameters last (e.g., avoid example.com/category?session-id=123&tracking-id=456&category=gummy-candies&taste=sour& in favor of example.com/category.php?category=gummy-candies&taste=sour&session-id=123&tracking-id=456)
• Configure Webmaster Tools URL Parameters if you have strong understanding of the URL parameter behavior on your site (make sure that there is still a clear click path to each individual item/article). For instance, with URL Parameters in Webmaster Tools, you can list the parameter name, the parameters effect on the page content, and how you’d like Googlebot to crawl URLs containing the parameter.
  
  URL Parameters in Webmaster Tools allows the site owner to provide information about the site’s parameters and recommendations for Googlebot’s behavior.
• Be sure that if using JavaScript to dynamically sort/filter/hide content without updating the URL, there still exists URLs on your site that searchers would find valuable, such as main category and product pages that can be crawled and indexed. For instance, avoid using only the homepage (i.e., one URL) for your entire site with JavaScript to dynamically change content with user navigation —  this would unfortunately provide searchers with only one URL to reach all of your content. Also, check that performance isn’t negatively affected with dynamic filtering, as this could undermine the user experience.
• Improve indexing of individual content pages with rel=”canonical” to the preferred version of a page. rel=”canonical” can be used across hostnames or domains.
• Improve indexing of paginated content (such as page=1 and page=2 of the category “gummy candies”) by either:
• Adding rel=”canonical” from individual component pages in the series to the category’s “view-all” page (e.g. page=1, page=2, and page=3 of “gummy candies” with rel=”canonical” to category=gummy-candies&page=all) while making sure that it’s still a good searcher experience (e.g., the page loads quickly).
• Using pagination markup with rel=”next” and rel=”prev” to consolidate indexing properties, such as links, from the component pages/URLs to the series as a whole.
• Include only canonical URLs in Sitemaps.

Remember that commonly, the simpler you can keep it, the better. Questions? Please ask in our Webmaster discussion forum.

Written by Maile Ohye, Developer Programs Tech Lead, and Mehmet Aktuna, Crawl Team

Webmaster level: intermediate-advancedIn the past, we have seen occasional confusion by webmasters regarding how crawl errors on redirecting pages were shown in Webmaster Tools. It’s time to make this a bit clearer and easier to diagnose! While it used…

Webmaster level: intermediateTo help jump-start your year and make metrics for your site more actionable, we’ve updated one of the most popular features in Webmaster Tools: data in the search queries feature will no longer be rounded / bucketed. This c…

Webmaster Level: All

Search Queries in Webmaster Tools just became more cohesive for those who manage a mobile site on a separate URL from desktop, such as mobile on m.example.com and desktop on www. In Search Queries, when you view your m. site* and set Filters to “Mobile,” from Dec 31, 2013 onwards, you’ll now see:

• Queries where your m. pages appeared in search results for mobile browsers
• Queries where Google applied Skip Redirect. This means that, while search results displayed the desktop URL, the user was automatically directed to the corresponding m. version of the URL (thus saving the user from latency of a server-side redirect).

Skip Redirect information (impressions, clicks, etc.) calculated with mobile site.

Prior to this Search Queries improvement, Webmaster Tools reported Skip Redirect impressions with the desktop URL. Now we’ve consolidated information when Skip Redirect is triggered, so that impressions, clicks, and CTR are calculated solely with the verified m. site, making your mobile statistics more understandable.

Best practices if you have a separate m. site

Here are a few search-friendly recommendations for those publishing content on a separate m. site:

• Follow our advice on Building Smartphone-Optimized Websites
• On the desktop page, add a special link rel=”alternate” tag pointing to the corresponding mobile URL. This helps Googlebot discover the location of your site’s mobile pages.
• On the mobile page, add a link rel=”canonical” tag pointing to the corresponding desktop URL.
• Use the HTTP Vary: User-Agent header if your servers automatically redirect users based on their user agent/device.
• Verify ownership of both the desktop (www) and mobile (m.) sites in Webmaster Tools for improved communication and troubleshooting information specific to each site.

* Be sure you’ve verified ownership for your mobile site!

Written by Maile Ohye, Developer Programs Tech Lead

Now that 2013 is almost over, we’d love to take a quick look back, and venture a glimpse into the future. Some of the important topics on our blog from 2013 were around mobile, internationalization, and search quality in general. Here are some of the m…