1) SI CAPTCHA for WordPress
Author: Mike Challis
Adds CAPTCHA anti-spam methods to WordPress on the comment form, registration form, or both. In order to post comments, users will have to type in the phrase shown on the image. This prevents spam from automated bots. Adds security. Works great with Akismet.
* Configure from Admin panel
* Valid HTML
* Section 508 and WAI Accessibility Validation.
* Allows Trackbacks and Pingbacks
* Setting to hide the CAPTCHA from logged in users and or admins
* Setting to show the CAPTCHA on the comment form, registration form, or both
* I18n language translation support (see FAQ)
Captcha Image Support:
* Open-source free PHP CAPTCHA library by www.phpcaptcha.org is included
* Abstract background with multi colored, angled, and transparent text
* Arched lines through text
* Generates audible CAPTCHA files in WAV format
* Refresh button to reload captcha if you cannot read it
* Works with WordPress 2.6+
* PHP 4.0.6 or above with GD2 library support.
* PHP register_globals must be set to OFF.
* Your theme must have a <?php do_action(‘comment_form’, $post->ID); ?> tag inside your comments.php form. Most themes do. The best place to locate the tag is before the comment textarea, you may want to move it if it is below the comment textarea.
2) WP-SpamFree Anti-Spam
Plugin Link : http://wordpress.org/extend/plugins/wp-spamfree/
Author: Scott Allen
An extremely powerful WordPress anti-spam plugin that eliminates blog comment spam, including trackback and pingback spam. Finally, you can enjoy a spam-free WordPress blog! Includes spam-free contact form feature as well.
A Powerful Weapon Against Comment Spam
Comment spam has been a huge problem for bloggers since the inception of blogs, and it just doesn’t seem to go away. The worst kind, and most prolific, is automated spam that comes from bots. Well, finally there is an anti-spam plugin for WordPress that provides an effective solution, without CAPTCHA’s, challenge questions, or other inconvenience to site visitors. WP-SpamFree eliminates automated blog comment spam from bots, including trackback and pingback spam.
* Now with Enhanced Comment Blacklist option! Instead of just sending comments to moderation as with WordPress’s default Comment Blacklist functionality, with this turned on, anything that matchs a string in the blacklist will be completely blocked. Also adds a link in the comment notification emails that will let you blacklist a commenter’s IP with one click.
* See what’s been blocked! Version 2.0 adds “Blocked Comment Logging Mode”, a temporary diagnostic mode that logs blocked comments and contact form submissions for 7 days, then turns off automatically. If you want to see what’s been blocked, or verify that everything is working, turn this on and see what WP-SpamFree is protecting your blog from.
* Added option for smaller graphic counters to display spam stats, in addition to the existing normal-sized ones.
* Added Widget for displaying spam counter. Shows small counter #1. Now you can show stats without knowing any code.
1. Virtually eliminates automated comment spam from bots. It works like a firewall to ensure that your commenters are in fact, human.
2. A counter on your dashboard to keep track of all the spam it’s blocking. The numbers will show how effective this plugin is.
3. No CAPTCHA’s, challenge questions or other inconvenience to site visitors – it works silently in the background.
4. Includes drop-in spam-free contact form. Easy to use – no configuration necessary.
5. No false positives, which leads to fewer frustrated readers, and less work for you.
6. You won’t have to waste valuable time sifting through a spam queue anymore, because there won’t be much there, if anything.
7. Powerful trackback and pingback spam protection.
8. Easy to install – truly plug and play. Just upload and activate. (Installation Status on the plugin admin page to let you know if plugin is installed correctly.)
9. The beauty of this plugin is the methods of blocking spam. It takes a different approach than most and stops spam at the door.
10. The code has an extremely low bandwidth overhead and won’t slow down your blog (very light database access), unlike some other anti-spam plugins.
11. Completely compatible with all cache plugins, including WP Cache and WP Super Cache. Not all anti-spam plugins can say that.
12. Display your blocked spam stats on your blog.
13. Helps keep your database slimmer and more efficient.
14. Works in WordPress MU as well.
15. No cost, no hidden fees. Free for both Commercial and Personal use.
Plugin Link : http://wordpress.org/extend/plugins/mycaptcha/
Author: andre renaut
Allows you to display a captcha on your comment form to avoid spam.
Several choices of captcha style plus a random option.
Look and Feel totally compliant with WordPress 2.5
Requires GD php extension.
Supported languages : English, French (.pot provided)
Tested on Firefox2, Internet Explorer 7, Safari 3.1 (Windows XP)
Plugin Link : http://wordpress.org/extend/plugins/nospamnx/
Author: Sven Kubiak
NoSpamNX automaticly adds additional formfields to your comment form, invisible to the users. If a spambot fills these fields blindly (which 99.9% of all spambots do), the comment will not be saved. You can decide if you want to block these spambots, mark them as spam or put them in moderation queue. Furthermore, you can put common spam-phrases on a blacklist.
The user must no longer fill out any additional fields in the comment form, and you can focus on blogging and your readers comments!
Since Version 2.6 NoSpmaNX can use the same mechanics to protect your Registration and Login Form against automated access.
Make sure your theme loads wp_head and comment_form according to the WordPress Codex (see http://is.gd/1lezf), otherwise NoSpamNX will not work properly!
Features in a nutshell
* Easy installation (just activate the plugin)
* Does not require any modification on your comment template
* Does not change any of your comment formfields (giving you more compatibility with other plugins and templates)
* Does not require any extra field for user input (e.g. Captcha)
* No need to manage spambot comments anymore (if you don’t want to)
* Compatible with comments-popup
* Compatible with WordPress MU
* False-positives are nearly impossible
* NEW: Protect your Registration and Login Form against automated access (since 2.6)
Plugin Link : http://wordpress.org/extend/plugins/sabre/
Sabre is an acronym for Simple Anti Bot Registration Engine. It’s a set of counter measures against spam registration on your blog.
Your visitors are granted permission to register freely on your blog and now you are plagued by fake users automatically created by spammers? Sabre is the solution to stop definitely these robotized visitors!
List of available features:
- Inclusion of a captcha in the registration form
- Selection of the captcha’s complexity
- Selection of the background colour for the captcha image
- Inclusion of a math test in the registration form
- Selection of the math test’s complexity
- Random or fixed choice of the test to run
- Unobstrusive tests to detect if registration is done by humans or not
- Registration blocked if visitor’s IP address is found on ban lists
- The blog administrator can validate the user registration
- The user can validate his registration by clicking on a link sent by mail
- Limited number of days for user confirmation. Without beeing confirmed within the period of time, the user account is disabled
- Log on prohibited before user confirmation
- User is allowed to choose his password when registering on the blog
- User must agree with a warning text, disclaimer or general policy note when registrating
- User must give an invitation code during registration
- Main statistics displayed on the blog’s dashboard
- Custom logo on logon/registration screen
All these features are activated by parameters. Thus, Sabre is flexible enough and fits the protection policy you define for your blog.
NOTE 1: If you’re using an earlier version of WordPress, install Sabre 0.6.3 as Sabre 0.9.x is only compatible with WordPress 2.5 and up .
NOTE 2: If you are upgrading from a previous install, don’t forget to deactivate Sabre before overwriting the older files with the new ones. Then activate it again so Sabre can apply the required database and options updates.