Link Checkers

Change Detection Icon View tools in the Link Checkers category

Link checker is undoubtedly by far the largest category. So large in fact, that I don't see how we could come close to testing everything. Many of them are shareware or freeware, but those are not necessarily the best-written, most feature-packed, or most reliable. However, except for LinkScan, they don't tend to be too expensive, so perhaps this is a category where we could spend some of our software budget and get several products. Those products might very well prove useful for other projects.

Intended purpose:
Determine whether hot links (internal and/or external, relative and/or absolute) contained within a particular Web page or Web site are functional.

Potential for remote management:
Bad links are a fundamental indicator of poor Web site maintenance, so link checking should be an important component of any remote management toolkit.

Why do we care?
Missing content and/or broken links (even if the content is available somewhere) may be indicators of lax maintenance, or a site that's become too large or complex for the available personnel to maintain.

Characteristics?
Boundaries can usually be set (i.e. how many layers of links to test or whether to test external links). Most do testing by attempting to access the linked site and then reporting the HTTP status code returned. Some can be configured to detect and report meta-refreshes or to look for specific text (which might enable detection of "phantom" 404s, i.e. pages that return a status code indicating good content, but really contain "page not found" messages. However, most link checkers simply report as good any page that returns a status code of good, regardless of what content it contains.

Relationship to other categories: (should this category be used in conjunction with another category?)
Link checking is commonly carried out and reported by full-fledged Web crawlers. Other tools, such as site management and site mapping may do link checking as a part or prerequisite of some other task.

High or Low impact:
Depends on the complexity of the site and number of links. Has the potential to be high impact, which explains why some products are restricted for use on one's own site.

Can these tools be used on other sites or only on your own site?
In most cases, link checkers can be configured to check just about any site. However, license agreements for some products prohibit their use on any site other than one's own.