Wednesday, February 12, 2014

https://www.example.com/category.php?category=gummy-candies&price=5-10&price=over-10
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
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 home page or a category page.
Ideal for searchers and Google Search
-
Clear path that reaches all individual product/article pages
-
One representative URL for category page
https://www.example.com/category.php?category=gummy-candies
-
One representative URL for individual product page
https://www.example.com/product.php?item=swedish-fish
Undesirable duplication caused with faceted navigation
-
Numerous URLs for the same article/product
-
Canonical:
example.com/product.php?item=swedish-fish
-
Duplicate:
example.com/product.php?item=swedish-fish&category=gummy-candies&price=5-10
The 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), as demontrated in the following table:
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:
Where /c123/
is a category,