Links Inspector

Links Inspector is a powerful tool to know everything you need about the links in visited pages.
Once you have your pages crawled - be they a list of URLs with incoming links, or a normal site exploration - you can inspect links as you need. External, internal, inbound or outbound links, Visual SEO will help you to assess their real value.

Used in combination with the Crawl URL List feature, Links Inspector permits you to audit backlink profiles, automating many off-page SEO checks to help you understand whether the link passes PageRank, and whether the URL the link points to actually accumulates it and/or distributes it internally.

Links Inspector usage is straightforward:

1. depending on the type of analysis you need to perform, select the proper search criteria;
   

   

2. click on the Find links button;
3. and voilà, results will be loaded in the Link list table:

   

Search criteria

Match type

Links analysis can be performed to investigate various cases. The program will let you choose from several options:

Link match options

• Domain
  Will extract only the links pointing to the indicated domain. For example, if the indicated domain is "example.com", all links pointing to pages in "example.com" or "www.example.com" will be extracted.
• Exact domain
  Will extract only the links pointing to the indicated hostname. For example, if the indicated domain is "blog.example.com", all links pointing to pages in "blog.example.com" will be extracted, but not those pointing to pages to - say - "www.example.com" nor "example.com".
• Partial URL
  Will extract only the links pointing to the partial URL specified. For example, if the indicated partial URL is "www.example.com/Blog", only links pointing to pages in such folder will be extracted.
• Exact URL
  Will extract links pointing exactly to the specified URL.
• Exclude domain
  Will extract links not pointing to the specified domain. A typical usage scenario is when you want to locate all the external links in your site.
• Exclude exact domain
  Will extract links not pointing to the specified hostname.
• All links
  Will extract all links found. In this case the "Domain/URL to match" field is disabled and its content ignored.

Domain/URL to match

Insert in this field the domain, URL or partial URL you want to match the searched links against.
Depending on which option you select in the "Match type" drop down menu, this text field will suggest you the form of the input text.

If you use Links Inspector to perform a backlink profile audit - using a crawl session made of pages coming from a list of URLs downloaded via the Crawl URL List feature - and you specified as a crawl option a linked domain (recommended), that will be used to pre-populated the field (and - most important - the program will be able to assess whether the URL the link points to actually accumulates and/or distributes the received PageRank).

If the chosen match type is "All links", this field will be disabled and its content ignored.

Find links

Clicking on the Find links button the program will search within the pages of the crawl session all links matching the given search criteria.
Found results will fill the Link list table below.

Summary

The Summary tab sheet give you an overall perspective of the reports available in Links Inspector.
You can quickly select it anytime, even when not it is not visible, by clicking on the Show Summary link.

Summary: Toolbar

Links found

The total number of links found matching the given search criteria.

It is shown as a ratio of two numbers: the number of links found matching the criteria, over the number of all links found.
The program shows both the fraction and percentage forms.

The label is an active link: when clicked the "Link list" tab sheet will be selected.

Matching pages

The total number of pages found containing links that match the given search criteria.

It is shown as a ratio of two numbers: the number of pages found containing links that match the criteria, over the number of all pages analyzed.
The program shows both the fraction and percentage forms.

The label is an active link: when clicked the "Matching pages" tab sheet will be selected.

Non-matching pages

The total number of pages found not containing links that match the given search criteria.

It is shown as a ratio of two numbers: the number of pages found not containing links that match the criteria, over the number of all pages analyzed.
The program shows both the fraction and percentage forms.

The label is an active link: when clicked the "Non-matching pages" tab sheet will be selected.

Summary: tab content

The Summary tab gives you a visual overview of the links analyzed with a set of 3D pie charts, each giving evidence to a particular aspect:

Links Inspector summary page

• Links by type
• Links by anchor text
• Links by root domain
• Links by hostname
• Links by ability to pass PR
• Links by follow/nofollow

Like all 3D pie graphs in Visual SEO Studio, the charts can be zoomed, rotated, copied and saved at pleasure.

View details

When a summary graph has a corresponding tab sheet, below it a View details link, once clicked, will select the corresponding tab sheet.

Link list

The full list of the links matching the search criteria is a real time saver: it performs for you all the background checks to understand whether the links pass PageRank and whether it is not wasted by the receiving end.

Links Inspector link list (several columns are hidden)

Link list: Toolbar

Links found

The total number of links found matching the given search criteria.

It is shown as a ratio of two numbers: the number of links found matching the criteria, over the number of all links found.
The program shows both the fraction and percentage forms.

Show

Sometimes is better to "see less" in order to concentrate on a single aspect you want to analyze.
This option permits you to filter the links that matched the given search criteria and only show a subset of links matching common scenarios to be investigated in order to find links that could improve the overall website SEO.
Switching this option is instantaneous because you are just filtering the result set, not searching it again.

Link list, filtering options

• All matching links
  It is the default option: no filter is applied and the table lists all links matching the given search criteria.
• Links that can pass PR
  This option entry permits you to show only links that supposedly flow PageRank.
  We say "supposedly", because the search engine could decide to discard them for reasons the program cannot be aware of, e.g. disavowed links, automated demotion due to spam detection, and so on.
  A link can flow PR if it is not "nofollow" and the page where it is is not "nofollow".
• Links with destination URL not receiving passed PR
  This option entry permits you to show only links that flow PageRank but the destination URL is not receiving it.
  It could happen when the destination page does not exist, or would be reachable via a redirect chain longer than five hops, or in case of server error.
  The final destination URL needs to be crawled in order to compute the value.
  The common case of a page not found would be a good opportunity to recover the passed PageRank by simply creating the page, or setting a redirection to the most appropriate content.
• Links with destination URL wasting passed PR
  This option entry permits you to show only links that flow PageRank, the destination page receives it, but somehow it wastes it.
  "Wastes" means the destination page is marked as "noindex" (and thus cannot rank) and/or is marked as "nofollow" (and thus cannot in turn flow the gained PageRank to other internal pages). Also the case when the destination page is blocked by the robots.txt file is a waste of PageRank: it receives PR anyway, but wastes it as cannot position itself nor redistribute it internally.
  The final destination URL needs to be crawled in order to compute the value.
  The listed destination pages are representing opportunities to optimize the PageRank internal flow. It generally makes sense setting them as "follow", and if they are "noindex" you should also consider them as candidate pages to rank for the anchor text term by removing the "noindex" and optimizing their content.
• Broken links
  A "broken link" is a link pointing to a URL which does not exist, thus leading to a missing page (HTTP 404 "Not Found" or HTTP 410 "Moved").
  Broken links are a bad user experience and could also prevent the search engine bot discovering and ranking important site pages. They should be fixed by correcting the link URL.
  Note: until version 2.3.3 the tool adopted a broader definition including also links pointing to redirected URLs. These are now filtered by using the dedicated option "Redirect chains".
• Redirect chains
  A "redirect chain" is the hops sequence, of HTTP requests, a browser or a web spider takes to reach a landing page when the initial response codes are of the 3xx family.
  This option filters the list by showing only links pointing to redirected URLs. It permits you to inspect redirect chains by using the "Redirect chain" and "Destination status" columns.
  Redirected URLs are too (to a minor degree) bad user experience because they add an extra wait time before the user could visualize the final landing page content. They also have the effect of having the search engine spider taking longer to index the destination page because an extra URL visit has to be scheduled. When a redirect chain is caused by a link that has not been updated to a newer and correct URL, it should be fixed by using the final destination URL in the link.
• '_blank' without 'noopener' or 'noreferrer'
  When a link uses the target="_blank" attribute the browser opens its destination URL in another tab page. This is commonly used for links to external domains because you want to enrich your content with a link, but at the same time want to help your users not loosing orientation in navigating your web site.
  Unfortunately a malicious script in the external page could pose a security threat to your site (e.g. changing your page to a similarly looking "phishing"" website); with some older browser the attribute could also impair script performances if the link destination page makes heavy use of scripts.
  All this could be prevented by adding to the rel attribute the value 'noopener' ('noreferrer' would have a similar effect, even though it was conceived for another task). Keep in mind that the rel attribute can have multiple values, e.g. rel="noopener nofollow".

Shown

The number of links found matching the given search criteria and the filter selected in the "Show" option.

It is shown as a ratio of two numbers: the number of links listed after applying the filter, over the number of all links matching the given search criteria.
When the selected filter option is "All matching links", it is normal that the two numbers are the same, equal to the first number shown in the "Links found" field.

Choose columns

Clicking on the Choose columns you will be able to show or hide columns of the table.

Export

Clicking on the Export button a drop down menu will appear with the following options:

• Export to Excel
  Permits to export the content of the shown columns to an Excel document.
• Export to CSV
  Permits to export the content of the shown columns to a CSV file.

Search Analytics

Clicking on the Search Analytics button a drop down menu will appear with the following options:

• Add Google "Search Analytics" data (Source URL)
  Permits to add columns with data from Google Search Analytics related to the source URL.
• Add Google "Search Analytics" data (Destination URL)
  Permits to add columns with data from Google Search Analytics related to the destination URL.

Bing/Yahoo

Clicking on the Bing/Yahoo button a drop down menu will appear with the following options:

• Add Bing/Yahoo "Page Traffic" data (Source URL)
  Permits to add columns with Bing/Yahoo Traffic Page data related to the source URL.
• Add Bing/Yahoo "Page Traffic" data (Destination URL)
  Permits to add columns with Bing/Yahoo Traffic Page data related to the destination URL.

Mozscape

Clicking on the Mozscape button a drop down menu will appear with the following options:

• Add data from "Moz" (Source URL)
  Permits to add columns with data from Moz related to the source URL.
• Add data from "Moz" (Destination URL)
  Permits to add columns with data from Moz related to the destination URL.

Matching pages

The total number of pages found containing links that match the given search criteria.

It is shown as a ratio of two numbers: the number of pages found containing links that match the criteria, over the number of all pages analyzed.
The program shows both the fraction and percentage forms.

Link list: Column headers

Source URL

The absolute URL of the page containing the link.

Source page title

The title of the page containing the link, read from the title tag.

Destination URL

The absolute URL of the destination address pointed by the link.

Final landing page

The absolute URL of the final landing page reached by clicking on the link.
In normal cases, when the response code of the URL pointed by the link is "200 OK", it is the same as the "Destination URL".
In case of redirect (HTTP 3xx family response code), it is the URL of the final landing page reached at the end of the redirect chain.
If the redirect chain is not followed completely, it cannot be computed and its value will be blank.

Anchor Text

Anchor text is the text that in the HTML code appears between the link start <a> and end </a> tags.
When shown in a browser, link anchor text is sensible to the mouse click: by clicking on it user can navigate the destination URL. Browsers by default give the anchor text evidence showing them in blue underlined text; this behavior is often overridden by webmaster though to better align to the website style.

CSS path

The CSS absolute path describes the location of the link using the CSS locator syntax, considering its complete hierarchy in the DOM of the HTML document.

Link type

Not all links were born equal. Even when they can pass PageRank, they are taken in better or worse consideration by search engines depending on their placement within the web page.
Content links are generally considered of higher value than - for example - footer links.
Visual SEO Studio has a powerful feature: it is able to classify the type of link. Recognized types are:

• Content
  The link is placed within the body of an article, blog post, etc. Content links are considered of higher value.
• Navigation
  The link is placed within a navigation menu, likely shared among all pages or a set of pages.
• Header
  The link is placed within the header part of the web page, likely shared among all pages.
• Footer
  The link is placed within the footer part of the web page, likely shared among all pages.
• Sidebar
  The link is placed within a side element of the web page, likely shared among more pages.
• Signature
  The link is placed within a forum or blog signature.
• Comment
  The link is placed within a user generated comment, e.g. a comment in a blog post.
• Unknown
  Used when the program was not able to categorize the link.

Links in source

Number of page links over which the PR is split (without self-reference URLs).

According to the original PageRank algorithm, the PR a page receives from another is the PR of the source page divided among the number of links present in the source page.
So when you examine a backlink profile and want to assess the value of a link from an authoritative web page, you should keep in mind that in terms of received PageRank it could be preferable - for example - having an inbound link from a PR3 page containing ten links than one from a PR4 page containing hundreds.
Links with self-referring URLs - i.e. links on a page pointing to the page itself, like links pointing to a page section using the # "pound" symbol (also named "hash" or "named anchor"), or links in the main menu pointing to the current page - are discarded in PageRank computation, so the program does not count them.

Can pass PR

States whether the link supposedly flows PageRank.
We say "supposedly", because the search engine could decide to discard it for reasons the program cannot be aware of, e.g. disavowed links, automated demotion due to spam detection, and so on.
A link can flow PageRank if it is not "nofollow" and the page where it is is not "nofollow".

Possible values are:

• when based on all directives computed, the link can pass PageRank
• when based on all directives computed, the link cannot pass PageRank

Destination receives PR

States whether the destination page pointed by the link receives PageRank from the it.

True if "Can pass PR" is true, and if the final (max 5 redirects) destination URL returns a "200 OK" status code.
The final destination URL needs to be crawled in order to compute the value.

Possible values are:

• when the destination page of the link receives PageRank
• when the destination page of the link does not receive PageRank
• when the program cannot establish it because the destination URL was not visited

The PageRank flowed by the link could not be received when the destination page does not exist, or would be reachable via a redirect chain longer than five hops (we use the 5 redirect chain rule to model Google behavior), or in case of server error.
The common case of a page not found would be a good opportunity to recover the passed PageRank by simply creating the page, or setting a redirection to the most appropriate content.

Destination wastes PR

States whether the destination page pointed by the link receives PageRank from the it, but somehow it wastes it.
"Wastes" means the destination page is marked as "noindex" (and thus cannot rank) and/or is marked as "nofollow" (and thus cannot in turn flow the gained PageRank to other internal pages). Also the case when the destination page is blocked by the robots.txt file is a waste of PageRank: it receives PR anyway, but wastes it as cannot position itself nor redistribute it internally.

True if "Destination receives PR" is true, and if the final destination URL is "noindex" or "nofollow". True also if the destination URL is blocked by robots.txt file.
The final destination URL needs to be crawled in order to compute the value.

Possible values are:

• when the destination page of the link wastes PageRank
• when the destination page of the link does not waste PageRank
• when the program cannot establish it because the destination URL was not visited

A destination page "wasting" PageRank is an opportunity to optimize the PageRank internal flow. It generally makes sense setting it as "follow", and if it is "noindex" you should also consider it as candidate pages to rank for the anchor text term by removing the "noindex" and optimizing its content.

nofollow

States whether the value of the optional rel attribute in the HTML markup of the link contains the value nofollow.
The rel attribute accepts multiple values separated by spaces.
The nofollow value tells the search engines not to follow the link - but a search engine could do it anyway for discovery purposes - and mostly suggests not to pass the so-called "link juice", a page value asset which in Google case is known as PageRank.
Visual SEO Studio spider doesn't follow nofollow links during a site exploration (unless explicitly asked via crawl options for verified sites), and takes it into account when evaluating whether the link passes PageRank.

Sponsored

States whether the value of the optional rel attribute in the HTML markup of the link contains the value sponsored.
The rel attribute accepts multiple values separated by spaces.
The sponsored value tells the search engines the link was paid for and should not to pass the so-called "link juice", a page value asset which in Google case is known as PageRank.
Visual SEO Studio spider doesn't follow sponsored links during a site exploration (unless explicitly asked via crawl options for verified sites), and takes it into account when evaluating whether the link passes PageRank.

UGC

States whether the value of the optional rel attribute in the HTML markup of the link contains the value ugc.
The rel attribute accepts multiple values separated by spaces.
The ugc value stands for "User generated content" and tells the search engines the link was placed there by a site user (e.g. a comment in a blog post) and should not to pass the so-called "link juice", a page value asset which in Google case is known as PageRank.
Visual SEO Studio spider doesn't follow ugc links during a site exploration (unless explicitly asked via crawl options for verified sites), and takes it into account when evaluating whether the link passes PageRank.

Source is 'index'

Indicates the "Index" property of the page containing the link.

Index value is computed from all generic and bot-specific directives via robots meta tag and X-Robots-Tag HTTP headers.
Possible values are:

• Blank, when based on all directives computed, the resource IS indexable
• when based on all directives computed, the resource is NOT indexable

Keep in mind that a "noindex" page can still accumulate and pass PageRank.

Source is 'follow'

Indicates the "Follow" property of the page containing the link.

Follow value is computed from all generic and bot-specific directives via robots meta tag and X-Robots-Tag HTTP headers.
Notice that if a nofollow were found in the HTML head or HTTP header, it will make all page links unexplorable, even if they don't have the rel="nofollow" attribute.
Possible values are:

• Blank, when based on all directives computed, page links are explorable
• when based on all directives computed, page links are NOT explorable

Source is canonical

States whether the page containing the link is Canonical.

A page is "the canonical version" - i.e. the preferred version to be indexed - when:

• it is "canonicalized" with a self referring canonical link tag:
  <link rel="canonical" href="...URL pointing to itself..." />
• or when the canonical link is missing, making the page implicitly canonical.

Incoming PageRank in non-canonical pages is considered as if flowing to the canonical version of the URL.
Non-canonical pages should be almost identical copies of the canonical one; think for example to an e-commerce website faceted navigation leading to non-canonical pages dedicated to variants in color of a good. When the page instead is largely different, search engines might discard the canonicalization suggestion.

When a link is present only in a non-canonical version, it is not clear how it impacts PageRank flow. Our experiments seem to demonstrate it is followed; most likely - but hard to demonstrate - PageRank of the canonical version flows through it as well, so outgoing PR should be split among a number of links which is the number of unique URLs linked by the page and its non-canonical versions.

Destination is 'index'

Indicates the "Index" property of the destination page pointed by the link.

Index value is computed from all generic and bot-specific directives via robots meta tag and X-Robots-Tag HTTP headers.
The final destination URL needs to be crawled in order to compute the value.
Possible values are:

• Blank, when based on all directives computed, the resource IS indexable
• when based on all directives computed, the resource is NOT indexable

Keep in mind that a "noindex" page can still accumulate and pass PageRank.

Destination is 'follow'

Indicates the "Follow" property of the destination page pointed by the link.

Follow value is computed from all generic and bot-specific directives via robots meta tag and X-Robots-Tag HTTP headers.
Notice that if a nofollow were found in the HTML head or HTTP header, it will make all page links unexplorable, even if they don't have the rel="nofollow" attribute.
The final destination URL needs to be crawled in order to compute the value.
Possible values are:

• Blank, when based on all directives computed, page links are explorable
• when based on all directives computed, page links are NOT explorable

Destination is canonical

States whether the destination page pointed by the link is Canonical.

A page is "the canonical version" - i.e. the preferred version to be indexed - when:

• it is "canonicalized" with a self referring canonical link tag:
  <link rel="canonical" href="...URL pointing to itself..." />
• or when the canonical link is missing, making the page implicitely canonical.

Incoming PageRank in non-canonical pages is considered as if flowing to the canonical version of the URL.
Non-canonical pages should be almost identical copies of the canonical one; think for example to an e-commerce website faceted navigation leading to non-canonical pages dedicated to variants in color of a good. When the page instead is largely different, search engines might discard the canonicalization suggestion.

When a link is present only in a non-canonical version, it is not clear how it impacts PageRank flow. Our experiments seem to demonstrate it is followed; most likely - but hard to demonstrate - PageRank of the canonical version flows through it as well, so outgoing PR should be split among a number of links which is the number of unique URLs linked by the page and its non-canonical versions.

Redirect chain

The sequence of HTTP status codes and URLs of the HTTP requests performed following a redirect chain starting from the URL pointed by the link.

The cell content is multi-line. In the Windows version the row height adapts to show all content lines. In the macOS version, while only the first line (i.e. the first hop of the redirect chain) is visible at first sight, you can see the whole content by hovering the mouse pointer on the cell to pop up a tooltip showing the whole cell content. You can also visualize and copy the cell content via context menu.
When exported to a spreadsheet, the cell content is exported and shown fully, with the spreadsheet row height sized to show all cell content lines.

If the status code of the URL pointed by the link is not a redirect (HTTP 3xx status code family), the value if blank. The destination URL needs to be crawled in order to compute the value.

Redirect loop

Indicates whether a redirect chain would potentially be infinite due to a circular reference.
Possible values are:

• Blank, when no redirect loop is detected
• when a circular reference is found within the redirect chain

A redirect loop occurs when a redirect points to an URL already requested in the redirect chain.
For example:

URL 1 > URL 2 > URL 3 > URL 2 > URL 3 > URL 2 > URL 3 [….]

Redirect loops are considered a bad error that impairs both SEO and User Experience (UX).
Search engines and browsers normally stop following the redirect chain when they detect a loop, to avoid being trapped in an infinite cycle.
Redirect loops prevent the search engine to index the desired page, and cause the user to see a non-user friendly browser error page, may be after some delay.

Redirect loops are a technical error that should be fixed on the server side. How to fix them, depends on the type of web server and how redirect are configured. Report the issue the web server system administrator, possibly with the details provided by the "Redirect chain" column.

Destination status

The HTTP status code of the destination page pointed by the link.

In case of redirection, the whole redirect chain is listed, each step separated by columns.
For example a normal result could be 200 and a result in case of redirection could be 301; 200.
The destination URL needs to be crawled in order to compute the value.

By hovering the mouse pointer on the cell you will pop up a multi-line tooltip showing the details of the full URL for each status code.

title

The value of the optional title attribute in the HTML markup of the link. Browsers usually use the title attribute value as a tooltip. Search engines can occasionally use the title value to associate a text to the link destination page, in particular when no anchor text is present.

target

The value of the optional target attribute in the HTML markup of the link. Attribute target tells the browser how to open the linked web page. For example target="_blank" will tell the browser to open the page in another tab sheet.

rel

The value of the optional rel attribute in the HTML markup of the link.
The rel attribute accepts multiple values separated by spaces.

Line

The line in the HTML file where the start tag of the link was found.
The cell is an active link; clicking on it will highlight in the Content or DOM side panel (depending on what you choose from the resulting context menu) the link start tag.

Position

The horizontal coordinate in the HTML file where the start tag of the link was found.
The cell is an active link; clicking on it will highlight in the Content or DOM side panel (depending on what you choose from the resulting context menu) the link start tag.

HREF value

The value of the href attribute in the HTML markup of the link. Attribute href can contain a relative or an absolute URL.

Link list: Context menu

The Link list table provides a context menu you can trigger by right clicking with the mouse on a page row:

• Copy source URL
  Copies in the clipboard memory the URL of the page containing the selected link.
• Browse source URL
  Navigates with the default browser the URL of the page containing the selected link.
• Copy destination URL
  Copies in the clipboard memory the URL pointed by the selected link.
• Browse destination URL
  Navigates with the default browser the URL pointed by the selected link.
• Show in code
  Selects the Content side panel and there highlights the link start tag.
• Show in DOM
  Selects the DOM side panel and there highlights the link tag.

Links by type

Not all links were born equal. Even when they can pass PageRank, they are taken in better or worse consideration by search engines depending on their placement within the web page.
Content links are generally considered of higher value than - for example - footer links.
Visual SEO Studio has a powerful feature: it is able to classify the type of link. Recognized types are:

• Content
  The link is placed within the body of an article, blog post, etc. Content links are considered of higher value.
• Navigation
  The link is placed within a navigation menu, likely shared among all pages or a set of pages.
• Header
  The link is placed within the header part of the web page, likely shared among all pages.
• Footer
  The link is placed within the footer part of the web page, likely shared among all pages.
• Sidebar
  The link is placed within a side element of the web page, likely shared among more pages.
• Signature
  The link is placed within a forum or blog signature.
• Comment
  The link is placed within a user generated comment, e.g. a comment in a blog post.
• Unknown
  Used when the program was not able to categorize the link.

This report groups links by link type, and provides a pie chart to show at a glance their distribution.

Links by anchor text

The anchor text - the clickable text forming the link - has historically been used by search engines like Google as a strong signal for the search term to rank the pointed page for.

<a href="...">anchor text</a>

Since this become common knowledge among the SEO community, it unfortunately caused the despicable spread of link spam and commerce of exact-match text links.
Search engines realized these were mining the foundation of their ranking algorithms based on considering links as third party votes for appreciated resources. They then developed anti-spam algorithms to detect fraudulent use of links to artificially inflate PageRank calculation and other link related ranking signals.

When analyzing a backlink profile, looking at the most used anchor texts can help you spot a natural vs an artificial distribution of links:

• A natural looking anchor text distribution typically has a large usage of brand name, naked domain, full home page URL, and branded keywords - all these pointing to the website home page - and a variety of long tail keywords pointing to specialized pages, mixed with non-informative text (e.g. "this page", or "here") and empty texts (case of image links).
• An artificial looking anchor text distribution on the contrary has a higher number of one/three "exact match" main commercial keywords as anchor text of links pointing to the home page, texts that are unlikely to be used so commonly by people spontaneously linking to a website.

So today you want both to have a number of inbound links with anchor texts geared toward your preferred keywords, so that you can rank for them, and you also want your backlink profile to look natural, to avoid incurring in anti-spam penalties.
If you are under the impression the two things were antithetic, you are correct. Balance is the key.

This report groups links by anchor text, and provides a pie chart to show at a glance their distribution.

Links by root domain

Examples of root domain, also called "naked domain" or "main domain", are example.com or example.co.uk or any other first/second level domain you can register from a registration authority, without the "www." or any other subdomain part.
Differently from subdomains, root domains are registered and administered by a distinct legal entity (e.g. a person, a company...).
Hostnames like www.example.com and blog.example.com have the same root domain example.com and are administered by the same entity.

A strong backlink profile has backlinks from diversified root domains, the more the better.
Every spontaneous link is appreciated, but having all backlinks from one or few root domains is not comparable to having the same amount of backlinks from a lot of distinct root domains: many backlinks all from the same root domain are like a single person highly recommending you. This often indicates links placed in a shared content part like a footer or a sidebar, or a banner, while the best backlinks are content links.
Of course, looking only at the root domains number does not tell the full story, you want to see their names: sometimes is better having backlinks from fewer root domains, if they are well-known authoritative sites, instead of many rubbish domains bought wholesale from the same spammer. Visual SEO Studio lets you check them all.

This report groups links by root domain, and provides a pie chart to show at a glance their distribution.

Links by hostname

Examples of host name are example.com, www.example.com, blog.example.com or example.co.uk; basically it the domain name.
The list of all hostnames includes both root domains and subdomains, whatever is found in the crawled URLs.
Keep in mind that subdomains are largely treated as subfolders, with some exceptions (it depends on who is registered to administer them, read Subdomains and SEO to know more about how search engines treat them).

This report groups links by hostname, and provides a pie chart to show at a glance their distribution.

Matching pages

This report lists all pages where the program did find links matching the given search criteria.
The list can be export to Excel/CSV or opened as a crawl session subset in Tabular View for further details.

Non-matching pages

This report lists all pages where the program did NOT find links matching the given search criteria.
The list can be export to Excel/CSV or opened as a crawl session subset in Tabular View for further details.

When you are auditing a backlink profile, for example using a crawl session created with the Crawl URL List function visiting all URLs of backlink pages exported from Google Search Console, if the link is not found it could mean it was removed from the web page (unless the crawled page were truncated before the link definition, in case use a higher maximum page size threshold).
This is an important piece of information for those who paid for backlinks.