Protect your site against bad bots by trapping them in a virtual blackhole.
Add your own virtual black hole trap for bad bots.
Bye bye bad bots..
Bad bots are the worst. They do all sorts of nasty stuff and waste server resources. The Blackhole plugin helps to stop bad bots and save precious resources for legit visitors.
How does it work?
First the plugin adds a hidden trigger link to the footer of your pages. You then add a line to your robots.txt file that forbids all bots from following the hidden link. Bots that then ignore or disobey your robots rules will crawl the link and fall into the trap. Once trapped, bad bots are denied further access to your WordPress site.
I call it the “one-strike” rule: bots have one chance to obey your site’s robots.txt rule. Failure to comply results in immediate banishment. The best part is that the Blackhole only affects bad bots: human users never see the hidden link, and good bots obey the robots rules in the first place. Win-win! ????
Using a caching plugin? Check out the Installation notes for important info.
Features
- Easy to set up
- Squeaky clean code
- Focused and modular
- Lightweight, fast and flexible
- Built with the WordPress API
- Works with other security plugins
- Easy to reset the list of bad bots
- Easy to delete any bot from the list
- Regularly updated and “future proof”
- Blackhole link includes “nofollow” attribute
- Plugin options configurable via settings screen
- Works silently behind the scenes to protect your site
- Whitelists all major search engines to never block
- Focused on flexibility, performance, and security
- Email alerts with WHOIS lookup for blocked bots
- Complete inline documentation via the Help tab
- Provides setting to whitelist any IP addresses
- Customize the message displayed to bad bots ????
- One-click restore the plugin default options
- Does NOT use or require any .htaccess rules
Blackhole for Bad Bots protects your site against bad bots, spammers, scrapers, scanners, and other automated threats.
Not using WordPress? Check out the standalone PHP version of Blackhole!
Check out Blackhole Pro and level up with advanced features!
Whitelist
By default, this plugin does NOT block any of the major search engines (user agents):
- AOL.com
- Baidu
- Bingbot/MSN
- DuckDuckGo
- Googlebot
- Teoma
- Yahoo!
- Yandex
These search engines (and all of their myriad variations) are whitelisted via user agent. So are a bunch of other “useful” bots. They always are allowed full access to your site, even if they disobey your robots.txt rules. This list can be customized in the plugin settings. For a complete list of whitelisted bots, visit the Help tab in the plugin settings (under “Whitelist Settings”).
Privacy
User Data: This plugin automatically blocks bad bots. When bad bots fall into the trap, their IP address, user agent, and other request data are stored in the WP database. No other user data is collected by this plugin. At any time, the administrator may delete all saved data via the plugin settings.
Services: This plugin does not connect to any third-party locations or services.
Cookies: This plugin does not set any cookies.
Credit: Header Image Courtesy NASA/JPL-Caltech.
Blackhole for Bad Bots is developed and maintained by Jeff Starr, 15-year WordPress developer and book author.
Support development
I develop and maintain this free plugin with love for the WordPress community. To show support, you can make a donation or purchase one of my books:
And/or purchase one of my premium WordPress plugins:
Links, tweets and likes also appreciated. Thank you! ????
Screenshots
Blackhole Settings Screen (showing default options)
Blackhole Bad Bots Screen (showing some example bots)
FAQ
Do you offer any other security plugins?
Yes, three of them:
Pro versions with more features available at Plugin Planet.
How is this plugin different than a firewall?
Blackhole uses its own “smart bot technology” that only blocks bots if they have demonstrated bad behavior. Firewalls typically are “static” and block requests based on a predefined set of patterns. That means that firewalls sometimes block legitimate visitors. Blackhole never blocks regular visitors, and only it blocks bots that disobey your site’s robots.txt rules. So the rate of false positives is close to zero.
The trigger link is not appearing in the source code?
In order for the plugin to add the trigger link to your pages, your theme must include the template tag, wp_footer()
. This is a recommended tag for all WordPress themes, so your theme should include it. If not, you can either add it yourself or contact the theme developer and ask for help. Here is more information about wp_footer(). Once the footer tag is included, the plugin will be able to add the trigger link to your pages.
Will this block good bots like Google and Bing?
No. Never. All the major search engine bots are whitelisted and will never be blocked. Unless you remove them from the whitelist setting, which is not recommended.
I think the plugin is blocking Chrome, Firefox, etc.?
Impossible because the plugin never blocks by user agent. It only blocks by IP address. No other criteria are used to block anything.
How to add bots to the Blackhole manually?
Question: Is it possible to block some bots by just adding them to blocked list and deny them Access to my website?
Answer: Not possible with the free version, but the Pro version includes an easy way to add bots manually (via the Bad Bots Log).
How do I add other bots to the whitelist?
Visit the plugin settings and add to the list.
How do I reset the list of blocked bots?
Visit the plugin settings and click the button.
How do I delete the example/default bot from the log?
Not possible with the free version, but can do with the Pro version.
How can I disable the email alerts?
Visit the plugin settings and click the button.
Is there a standalone version of the Blackhole?
Yes. Visit Perishable Press to download a PHP-based version that does not require WordPress.
Is there a Pro version of Blackhole?
Yes, the Pro version is available at Plugin Planet.
Is Multisite supported?
Not yet, but it’s on the to-do list.
Which IP address are added by default?
Your server IP address and your local (home) IP address (or whichever IP you are using when the plugin is installed).
Can I manually include the blackhole link?
Yes, you can add the following code anywhere in your theme template:
<?php if (function_exists('blackhole_trigger')) blackhole_trigger(); ?>
Should whitelisted bots contain exact names?
Question: Should whitelisted bots contain exact names, or can I just use partial names?
Answer: You can use partial names or full names, depending on how specific you would like to be with blocking. If you look at the default whitelisted bot strings, you will see that they are just portions of the full user agent. So for example you can block all bots that include the string “whateverbot” by including that string in the whitelist setting. It makes it easier to block bots, but you have to be careful about false positives.
What about WordPress automatic (hidden) robots.txt?
By default, WordPress will automatically serve a hidden, “virtual” robots.txt file to anything that requests it. Once you add your own “real” robots.txt file, WordPress will stop generating the virtual one. So when it comes to WordPress and robots.txt, real trumps virtual. Blackhole Pro requires that you add some rules to an actual robots.txt file, but it does not create/add any robots rules or the robots.txt file for you. Check out the plugin’s Help tab for more infos.
Which WP caching plugins are compatible with Blackhole?
Check out the section on “Caching Plugins” in the plugin documentation
Does Blackhole clean up after itself?
Yes! As explained in the “Uninstalling” section in the plugin documentation, when Blackhole is uninstalled via the Plugins screen, it removes everything from the database. After uninstalling, don’t forget to remove the blackhole rules from your robots.txt
file. Then there will be zero trace of the plugin on your site.
How to disable the hostname lookup?
By default, the plugin uses PHP’s gethostbyaddr()
function to lookup the host name for blocked requests. This is fine on most servers but some may experience slight reduced performance. So for those who may need it, the following code snippet can be added to disable the host lookup:
function blackhole_enable_host_check() { return false; }
add_filter('blackhole_enable_host_check', 'blackhole_enable_host_check');
That code can be added via your theme (or child theme) functions.php, or add via custom plugin.
How to disable the error log entries?
By default the plugin adds an entry in the site error log for any invalid IP address. To disable this feature, add the following code snippet to your (child) theme’s functions file, or add via custom plugin:
function blackhole_validate_ip_log_custom($log, $ip) { return ''; }
add_filter('blackhole_validate_ip_log', 'blackhole_validate_ip_log_custom', 10, 2);
How to enable Blackhole protection on Login Page?
By default, Blackhole never blocks anything on the WP Login Page. This is to prevent new users from accidentally getting locked out of their site.
To change the default behavior, and add Blackhole protection to the Login Page, add the following code to theme or child theme’s functions.php, or add via custom plugin:
function blackhole_ignore_login($ignore) { return false; }
add_filter('blackhole_ignore_login', 'blackhole_ignore_login');
If you get locked out inadvertently, simply remove the code and the Login Page will be accessible once again.
How to prevent automatic robots.txt rules?
By default, Blackhole will automatically add the required rules to your site’s robots.txt file. This happens only when using WordPress’ auto-generated robots.txt file.
So if you would rather add the rules yourself, and not have Blackhole make any changes to robots.txt, simply add a physical robots.txt file instead of using the one that otherwise would be generated by WordPress. When an actual/physical robots.txt file exists in your site’s root directory, WordPress will not auto-generate one, and thus Blackhole will not add any rules or make any changes.
Got a question?
Send any questions or feedback via my contact form
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