Web browsers furthermore do not hinder a user to bookmark a website for a second time. Some may visualize that a bookmark already exists but none will stop the user from bookmarking a web page multiple times.

Bookmark Sentry for the Google chrome browser is a browser extension that can scan all bookmarks for dead and duplicate links.

The extension scans all browser bookmarks automatically after installation. This can take some time depending on the number of bookmarks and the folder structure.

The scanner displays the scan progression in the extension’s options. It shows the bookmark that is currently scanned, the percentage as a bar and number, the last scan, next scheduled scan and the number of problems found (which either means dead or duplicate bookmarks).

Scan results are displayed on the very same screen after a scan for duplicate or dead bookmarks finishes.

The extension displays status codes and text to make it easier for the user to identify the underlying problems. Each bookmark can be removed individually by clicking on the X at the front of each result. There is no option to delete all at once. Links are clickable to manually recheck the bookmark in question.

Bookmark Sentry will scan all bookmarks once a month by default. It is possible to change the interval to another or switch to manual checks only. The only other available preference is the time between connection scans. The default time is 10 seconds, reducing it will increase the scan speed.

Bookmark Sentry is a helpful extension for the Chrome browser. Most users are probably fine with running the extension once to check their bookmarks and disabling or uninstalling it afterwards. Only heavy bookmark users may need to use it regularly.

Update: The add-on has been removed from the Chrome web store. A Chrome extension alternative is not available. Windows users can use AM Deadlink instead which supports the Chrome browser as well.

• Opera up to the latest Opera 10
• Internet Explorer up to Internet Explorer 8
• Google Chrome up to Google Chrome 4
• Mozilla Firefox up to Firefox 2

Yes you read that right. The bookmark verifier supports all major web browsers except Safari. All versions of the supported web browser are compatible with the software program except for Firefox 3. This is due to the way Firefox 3 saves its bookmarks (in a database instead a plain file). The developers have stated that they will not add support for Firefox 3 (although they could technically) because they have no “plans to to hack into foreign databases”.

The program interface itself has not changed much. AM-Deadlink will load the bookmarks of all supported and installed web browsers on startup. These bookmarks are then displayed. A click on the check bookmarks button will start the check. It might be a good idea to pay a visit to the options first to configure connection settings or proxies.

There is also a way to check the Firefox 3 bookmarks with AM-Deadlink. This is done by exporting Firefox 3 bookmarks as HTML. This HTML file can then be checked with the bookmark verifier. Bookmarks that are not longer working can be removed from the file which can then be imported into Firefox 3 again. This will add the bookmarks to the existing bookmarks which will result in a massive list of duplicate bookmarks. You might want to delete all existing bookmarks first before importing the checked bookmark file. Just make sure you have a backup at hand in case something goes wrong in the process.

AM-Deadlink 4 can be downloaded from the developer’s website. It is compatible with all versions of Microsoft Windows from Windows 9x to Windows 7.

Check Places for Firefox adds the option to verify all bookmarks in the Firefox web browser. It can be used to check all bookmarks (with the option to exclude folders) or only specific folders that the Firefox user selects.

A click on the check bookmarks button will start the verification. The time it takes to verify the bookmarks depends on the amount of bookmarks and the Internet connection.

It took about a minute to check 489 bookmarks on a fast Internet connection. The add-on will display statistics on the report page including the time it took to verify the bookmarks and the number of bookmarks that got verified.

Errors are divided into the three categories failed pages, duplicates and empty folders. Failed pages are those with dns, page or other errors. These pages can be temporarily or permanently unavailable.

Each bookmark is listed in its own row. Selecting a bookmark will display additional information about the bookmark with the options to open, delete or exclude the bookmark.

The whole process – even if the pages with errors are verified manually – takes less than five minutes to complete.

Check Places is an add-on for the Firefox 3 web browser. It can be downloaded from the Mozilla Firefox website.

AM-DeadLink is a third party software that can check the bookmarks of all major browsers (Internet Explorer, Firefox, Opera and Mozilla) as well as url files, comma separated and tab delimited files. The Internet Explorer bookmarks are discovered automatically while all others have to be manually selected from the hard drive. The selections will be remembered in the future.

The main purpose of AM-DeadLink is to check all bookmarks. Error codes and additional information are displayed during and after the check and the dead bookmarks can be checked manually by opening them in the default browser or viewed internally. Favicons can be downloaded optionally if desired during the check.

The software can also search for duplicates in the list of bookmarks and delete those duplicates. The duplicate bookmarks can be deleted automatically by the program or manually by the user.

The program is pretty easy to use and gives the user enough freedom to make the important decisions. A great way to check all the bookmarks. It would be nice if there would be a way to check bookmarks of all browsers and sync them afterwards.