Today we are going to focus on tools that help you reveal dead links on your website. We have created a large set of tests that cover ways to link a resource in HTML4, HTML5, and CSS3. Using these tests we were able to evaluate many free broken link checker tools. Sadly, we found out that few tools are really usable. So, which tool is the best link checker?
Selecting Link Checkers for the Test
Which tools did we test? Here are the criteria that we used to select tools for our testing:
- We went through the first 40 results returned by Google for search query broken link checker.
- We required the tool to be able to check links on remote websites.
- The checker had to be free to use even if some limitations applied. If there were limitations, however, they had to allow using the tool reasonably.
- The checker had to be able to check pages recursively, which means that it was not necessary to manually run the tool for every page you want to check, but the tool was able to crawl the whole website automatically. This feature is crucial for any link checker that is intended to be used seriously.
Checkers We Tested
A list of link checkers that we tested thoroughly follows together with a table with basic information on checkers’ features and their final score. Note that we used penalty-based scoring system (fully described below) and hence the best possible result was -0.00. The worst possible result was -219.60. Every checker was expected to score better than -106.20, because this was the score that would be reached by a hypothetical checker that would do nothing and report no results (and thus make no false positive errors).
Tested link checkers:
- Online Website Link Checker – Our checker. Excellent checker, the winner of the test.
- W3C Link Checker – Excellent checker, missed very few bad links.
- LinkChecker 9.3 (by Bastian Kleineidam) – Very good checker, missed few bad links.
- Web Link Validator – Very good checker, missed few bad links.
- Xenu’s Link Sleuth(TM) – Decent checker, revealed most broken links, but also missed some.
- Link Valet – Poor checker, missed many bad links.
- Linklint – Poor checker, missed many bad links.
- Dead Link Checker – Poor checker, missed many bad links.
- Online Broken Link Checker – Poor checker, missed many bad links.
- Dr. Link Check – Poor checker, missed many bad links.
- Integrity for Max OSX – Poor checker, missed many bad links.
- Internet Marketing Ninjas Find Broken Links, Redirects & Site Crawl Tool – Very poor checker, missed almost all bad links, probably a broken tool.
|Tool||Type||Share/Export||Error Location in Source||Task Size Limitation||Total Score|
|Online Website Link Checker||Online Tool||YES||YES||10000 links||-0.00|
|W3C Link Checker||Online Tool||NO||YES||150 pages||-11.20|
|LinkChecker 9.3||Desktop Application||YES||YES||No limits||-18.10|
|Web Link Validator||Desktop Application||YES||YES||500 links||-19.90|
|Xenu’s Link Sleuth(TM)||Desktop Application||YES||NO||No limits||-38.50|
|Link Valet||Online Tool||NO||NO||Timeout for larger tasks||-63.70|
|Linklint||Desktop Application||YES||NO||No limits||-83.30|
|Dead Link Checker||Online Tool||NO||NO||Unknown||-85.20|
|Online Broken Link Checker||Online Tool||NO||YES||3000 pages||-93.40|
|Dr. Link Check||Online Tool||YES||NO||1000 links||-93.70|
|Integrity||Desktop Application||YES||NO||No limits||-96.00|
|IMN FBLRSCT||Online Tool||YES||NO||10000 links||-105.40|
Checkers We Did Not Test
The list of checkers that appeared in the search result but did not meet other criteria, and reasons why not tested:
- LinkChecker 0.6.7 – Browser extension that is only able to check visible links on one page.
- The Free Online Link Checker – Only able to check links on one page.
- SortSite Free Trial – A free version of this tool only reports 4 results, which is unusable.
- Check My Links – Browser extension that is only able to check visible links on one page.
- Submit Express Broken Link Checker Tool – Online tool that always reported Internal Server Error, so it was not possible to make any check.
- Webmaster Toolkit Link Checker – Only able to check links on one page and only 60 links.
- Site24x7 Link Checker – Only able to check links on one page.
- AnyBrowser.com Link Checker – Only able to check links on one page.
- LinkTiger – Asks for a registration and then does not show you the results unless you fill in a credit card number. Only 15 days free trial even if you provide credit card number. We do not consider this tool to be free to use.
- WordPress Broken Link Checker – CMS extension that is not designed to check links on remote websites.
- iWEBTOOL Broken Link Checker – Only able to check links on one page.
- Small SEO Tools Websites Broken Link Checker – Only able to check links on one page.
- Qlue Broken Link Checker – CMS extension that is not designed to check links on remote websites.
- Drupal Link checker – CMS extension that is not designed to check links on remote websites.
- IT-India Broken Link Checker – Only able to check 6 pages, which is unusable.
Tests and Scoring System
The set of tests used to evaluate link checkers can be found here: http://campredit.wz.cz/. This is a free web hosting site with a banner inserted into the content, which was not part of the test. Due to limitations of some checkers, we have divided the test set to six parts accessible from the main page. Each testing page contains a single link that is either a broken link or a good link, we use suffix -bad for test pages with broken links. Most of the methods of linking to a resource in HTML4, HTML5, or CSS3 can be written in three ways – an absolute link, a link relative to the location of the source document, a relative link to the root of the website. In our set, absolute link variants have suffix -abs, root relative have suffix -rel, source page relative are without any suffix.
In total, we have created 315 different tests, each representing a different scenario. However, we did not consider all tests as equally important. For example, HTML4 supports some outdated, poorly supported ways to link a resource, which are no longer available in HTML5. This was why we decided for a following scoring system. All tests that used HTML5 and CSS3 methods and methods that are often used in today’s web pages were considered as very important and their value was set to 1 point. All other tests were considered as less important and their value was set to 0.1 points. From 315 tests, we had 209 very important tests for 1 point and 106 less important tests for 0.1 points. The total number of points was thus 219.60.
About a half of the tests contained good links (total value of 113.40 points). These tests were present to reveal faulty link checkers that report good links as broken. So a tested link checker passed these tests in case it did not report good links as broken. This was also why we decided to go for the penalty-based scoring system. Each failed test meant deducting the test’s value from the tested checker’s score, starting with 0.00 score. In case of a good link test, the test was passed if its link was not marked as broken or not mentioned at all in the report, and it was failed if it was marked as broken in the report. In case of a bad link test, the test was passed if its link was marked as broken in the report, and it was failed if it was not found or not marked as broken in the report. A hypothetical link checker that would reported nothing would simply pass all tests with good links (by not reporting them as broken) and fail all tests with bad links (by not reporting them as broken) and would score -106.20.
The best possible score was thus -0.00 points, which would mean that the checker correctly reported all bad links and no good links were reported as bad links. The worst possible result was -219.60 points, which would mean that all good links were marked as bad links and no bad links were found or marked as bad links. Fortunately, this was only a theoretical limit and all tested link checkers scored even better than -106.20 points :-).
If you are looking for a good link checker, you have some, but not many, choices. For an online tool, go with our Online Website Link Checker or W3C Link Checker. If you prefer desktop applications for Windows, then you can try LinkChecker 9.3 (by Bastian Kleineidam) or Web Link Validator. These tools and applications will do the job very well. Xenu’s Link Sleuth(TM) is another very popular Windows application that can be used for website link checking but it may miss some bad links on your web pages.