Directions / Reference
Canonical Tags are used by search engine crawlers (your visitors will never see these tags on your website) to clear up confusion about which pages on your website should have the most value.
A website may have multiple pages that are very similar with near-identical content, copy, etc. A search engine will see this as duplicate content and get confused as to which of these near identical pages is more important. The result is they are unsure which page to show in the search results for a given search term.
An example of this is an ecommerce category page - like laptop computers. Many sites will offer filters on the left hand side to narrow a search result. The user chooses a brand, color, and screen size. This now generates 4 different pages that all list the laptops found on the site. While this is good for user experience, it's not good for search engines as they are un-sure which page on your website will display all of your laptops and thus should be given the most credit for a search of "laptops" in the search engine.
Adding a canonical tag to each of the "filter" pages back to the main laptop category page will tell the search engines that the main laptop category page is the one that you wish to have them index, and thus show to their users when searching for laptops. This effectively reduces the number of pages on your website in the eyes of a search engine. While that seems scary at first, this is actually a good thing as you now will have one strong powered page for laptops that a search engine can make a clear decision on how to rank.
Now admittedly, this example is very basic and simplified and every site needs to do deeper analysis about their individual situation. For certain products or pages, attributes such as color, brand, etc. are highly searched and you would not want to canonical those back up to the parent category. However pagination, price, etc. are filters you most likely would want to still add canonical tags to. So use these with careful analysis about the specific websites needs - possibly implementing some tags, see if it positively or negatively affects your rankings over the next few weeks or months, and adjust as needed.
Enter in a list of URLs to be returned the canonical tags and their respective HTTP response code
If the requested URL returns a redirect HTTP response, the redirect path will be followed to a 200 OK response.
While only one canonical tag per page is recommended, all canonical tags on a given URL are returned.
URL Delimiter:
Choose your separation method from the radio buttons based on how you will be entering your URLs to check. Typically your data has a default separator in place, depending on where your data is coming from (Google Webmaster Tools, PPC software, affiliate reporting, etc.)
- New Line: Common for manual entry, just press enter/return and place each URL on its own line.
- Comma: Also known as CSV. Used when URLs are separated by a comma and all are on one line/long text string.
- Semicolon: Similar to a comma separation listed above. All URLs should be on one line/text string.
- Tab: Used with tab delimited text input. All URLs should be on one line/text string.
Canonical Tag Response:
The following canonical tag responses will be displayed for each URL searched:
- No Canonical Tags found at this URL: No canonical tags were found at the requested URL.
- Canonical Tag: The URL in the canonical tags will be displayed with their HTTP Header Response code.
Response Type:
The HTTP Header Response Tool will return the following codes:
- 200 OK: A 200 OK means that the destination domain and page responded correctly. This means a visitor will be able to view the content they intended on seeing.
- 301 Redirect: A 301 redirect means that the URL you entered got redirected (sent to) another URL. There are several redirect codes, but the 301 means that this content has permanently moved. This is commonly used when a site changes its URL structure, a page/product name changed, etc.
- 302 Found: A 302 Found means the website was reached, but was redirected. Typically a 302 status means the URL is temporarily redirected, as opposed to the permanent 301 redirect.
- 404 Error: A 404 error means that the destination domain did respond, however the page you requested was not found. This typically means the page is broken and a visitor would not see what they expect when landing on this page. Typically you will want to investigate and correct this response type.
- 501 Error: A 501 error means that the destination server is unreachable. This means the site is effectively down.