Broken Link Checker for WordPress
Sometimes, links get broken. A page is deleted, a subdirectory forgotten, a site moved to a different domain. Most likely many of your blog posts contain links. It is almost inevitable that over time some of them will lead to a “404 Not Found” error page. Obviously you don’t want your readers to be annoyed by clicking a link that leads nowhere. You can check the links yourself but that might be quite a task if you have a lot of posts. You could use your webserver’s stats but that only works for local links.
So I’ve made a plugin for WordPress that will check your posts (and pages), looking for broken links, and let you know if any are found.
Download it now! (40 KB)
Note : This page, and the feature list below are slightly out of date as a major update has been released recently (see details). I’ll get around to updating this page eventually.
Features
- Checks your posts (and pages) in the background (whenever the WP admin panel is open ).
- Detects links that don’t work and missing images. Checks both internal and outbound links.
- Notifies you on the Dashboard if any problems are found.
- Link checking intervals can be configured.
- New/modified posts are checked ASAP.
The broken links show up in the Manage -> Broken Links tab. If any invalid URLs are found a notification will also show up in the sidebar on the Dashboard.
The Broken Links tab displays a list of invalid URLs found along with the relevant posts and the anchor text of the links. “View” and “Edit Post” do exactly what they say and “Discard” will remove the message about a broken link, but not the link itself (so it will show up again later unless you fix it; this plugin doesn’t modify your links).
By default all old posts/links are re-checked every 72 hours, or you can set a different time period.
Notes (Semi-Technical)
I realize there’s a lot of features that could be added to improve this plugin considerably. However, this release is intended to “test the waters” and see if there’s demand for a plugin like this, so I only implemented the most basic functions. The plugin has been upgraded to be slightly beyond “basic” 
I thought about using WP’s pseudo-cron to run the link checker by schedule and decided against it. AFAIK the cronjobs execute when a page is requested; since this plugin does some lengthy processing it may increase page load times unacceptably when used in this manner. That’s why I set it to run the checks asynchronously (AJAX) and invisibly in the admin panel.
Installation
Just like any other WordPress plugin -
- Download (see below).
- Unzip.
- Upload the broken-link-checker folder to you wp-content/plugins directory.
- Activate the plugin in the Plugins tab.
Upgrading
- Deactivate the plugin (important!).
- Do steps 1.-3. from “Installation”.
- Upload the broken-link-checker folder to you wp-content/plugins directory.
- Re-activate the plugin in the Plugins tab.
Download
Version 0.5.3 : broken-link-checker.zip (40 Kb)
Requirements
- WordPress 2.7 or later
- MySQL 4.1 or later
Starting with version 0.5 this plugin is only compatible with WordPress 2.7 and up. Older versions (e.g. ver. 0.4.14) should work with WP 2.1 – 2.6.x.
White Shadow, you already have everything you need to implement what I mentioned (The click on the link and it shows an input box for faster link fixing). You already have the Regular Expressions in the wsblc_ajax.php file, just make a callback like unlink_link_callback and use a different $matches variable (Maybe $matches[0] I think is the href, not positive), the SQL queries already seem to be fine. The only major change will be adding the input box and all of that, and you can see an example of that in the wp-admin\js\slug.js file, the first function, edit_permalink. This function is the one that shows the input box and all of that.
I’m not trying to say it’s absolutely easy and bashing you for not doing it or anything, I would do it if I had a better understanding of this, just trying to help you out with some clarifications. If you ever want to give it a try, I’ll be glad to test it out for you. Like I said earlier, I’m /positive/ that every one of your users will benefit from this. It’d definitely be faster than having to click edit post for each post and look through the long post to find the link. Not trying to nag or anything though I know it’ll probably seem this way, just trying to show that I really care about this feature enough to investigate.
Ahem. It definitely isn’t easy. I tried, and got weird and unusual MySQL errors that I couldn’t trace to any particular source. Still, I’ve uploaded an experimental implementation to wordpress.org (you should get an “upgrade available” notice in your “Plugins” tab).
Hmm…don’t know what errors you’re talking about, where do you get them and when? I’ve tried the new plugin and it works perfectly, really, I’ve tried it multiple times.
One weird thing is that when I click view post on some of them, it uses my old domain name, only on posts that were created when I had that domain name, but I’m not sure if it’s your plugin’s own doing.
Well, you never know when a bug might crop up
The plugin gets the URL for the “View” link from the WordPress database (using the “guid” filed). Some of your older posts probably have outdated database info. I think.
Yeah I figured that out by viewing your plugin’s source, I simply ran a REPLACE query on the guid table so that’s fixed now. The only problem is that some of the guid’s are of when I used different permalinks (for example /p?=432) and as far as I can tell there’s no way of fixing that (I already tried update permalinks). Oh well, but hey at least your plugin is working perfectly fine. If I ever notice anything then I’ll hit you up.
You should announce this new feature man, I’m positive you’ll get a lot of attention for it and many people will love it. It would’ve been neater if you could do it like the slug editing is: The URL is just text and when one clicks on it it becomes the textbox and when one clicks outside of it or on the save link/button it saves it (If not the former then at least the latter). This would be a lot more intuitive and make for a smoother process. But hey at least it’s working now, perfectly fine too! This suggestion is just as a touch up.
I’ll let you know if anything happens but so far the plugin is working great. If you need anything let me know!
I suspect nearly 30% of my posts are about new plugins/features. So I’d rather skip posting about small updates
Hi,
Thanks for your amazing plugin!
I have a request for an enhancement.
I went through the source code and noticed that the “View” links are generated according to the the GUIDs. This may cause problems on non-English blogs, such as my blog in Chinese. I think using permalinks is a better approach. Hope this helps!
Thanks again.
Regards
Leo
Ahha, and how do I get the permalinks? (It’s probably not extremely hard, but I didn’t figure it out when writing that code)
You can probably use get_permalink, giving it the post’s ID as the parameter. This function is provided by WordPress core.
Anyway I’ve not tried that yet. Good luck with that! We can find a way out together if you are faced with any coding problem.
Interesting, that seems to work. I’ll have a new version up soon, thanks
Yeah I was about to tell you to do what Leo said, it’s definitely better and more logical.
hey white shadow, as mentioned in my pioneer (around 10 to 20) comment earlier in the development of your genius plugin – I do still get the unlink error.
only occurs with images (wikipedia and my own), do you have any idea how to fix that?
cheers,
jez
I didn’t figure it out at first, but now I know it doesn’t work because I haven’t added any specific “image-unlinking” code. So the “Unlink” button only works for links.
Maybe one day
[...] noarchive) along with Nofollow Case by Case. Add in Google XML Sitemaps, Ozh’ Better Feed, Broken Link Checker and PagerFix if/as applicable, for bonus [...]
This is a very cool plug-in but I’m having some trouble with it. It’s constantly reporting many valid URLs as if they were invalid, aside from catching the occasional invalid one. I’ve experimented with the settings to no avail. I’m running 2.5… Any suggestions? Thanks
It’s possible that those links that are incorrectly reported as broken point to websites that employ some kind of anti-bot protection, which might block the link checker. This has already happened before.
Another possibility is that the “broken” links load very slowly, so the connection times out and the plugin assumes the links don’t work.
Yeah… I’m seeing it happening now on multiple blogs, each of which aren’t having load time issues and are also running plug-ins like Bad Behavior, AntiLeech and/or others (many of the URLs reported as invalid are internal)… I’ll play with different configurations to try to pin down where the incompatibility lies. thx
[...] Broken Link Checker: And lastly I like this plugin because it shows me what posts have broken links on them so I can correct the problems and eliminate future seo problems because of missing pages! Last 10 posts in Readers QuestionsQuestions Need Answers #1 – May 24th, 2008Advertisments For Technology – April 14th, 2008What Are Authority Sites? – April 3rd, 2008Readers Questions – February 4th, 2008 Share and Enjoy: These icons link to social bookmarking sites where readers can share and discover new web pages. [...]
Nice plugin! Thanks a lot! I hope that in future version could check broken links in comments too.
I’m testing comments to see if the DNS issue is on my end, or somewhere else.
Hi,
How can i use link checker for rapidshare or mu links?
Is it work for those?
@Piklog – I suppose it should work for those as well, but I haven’t tested it.
I’m new wp user, can you test it for me?
I think RS, MU links are different from direct link checking.
It’s different.
thanks
@Piklog – Ah okay, you’re just being lazy here, how hard would it be to add a RS link to a post and see if the link checker catches it?
Anyway, I tested it, and it doesn’t work for them. Apparently RS won’t report the standard 404 HTTP code when a file is missing. Shame on them.
[...] 4. Broken Link Checker [...]
Hello! I made the Broken Link Checker translatable.
It’s here – http://mistress.hweia.ru/2008/06/broken-link-checker/ (the post is in russian, but it’s the only .zip there, hard to miss
@Anna – Thanks. I fixed a few things (that shouldn’t have been translater) and will upload a new version soon.
By the way, I understand Russian just fine, though I’m not russian myself.
[...] should thank W-Shadow for providing us with this automatic broken link checker plugin for WordPress. And you may also want to check outgoing links using bad neighborhood checker [...]
After activating I get this:
Aborting: WordPress API Malfunction
For some reason the function get_currentuserinfo() did not behave as expected. Your user_level seems to be null. This can be resolved by navigationg to the Users section of the WordPress administrative interface. In this section check the user that you use for administrative purposes. Then under the drop down labled “change role to…” select administrator. Now click the change button. Should you still recieve this error please report this bug to the plug-in author. In your report please specify your WordPress version, PHP version, Apache (or whatever HTTP server you are using) verion, and the version of the plug-in you are using.
WordPress version: 2.5.1
PHP version: 4.4.7
Plug-in version: 2.1.2
@tino – I don’t have the slightest idea why that happens. Also, I think you’ve got something wrong here, as none of my plugins are currently on ver. 2.1.2