Got a spambot or scraper constantly showing up in your server logs? Or maybe there's another site that's leeching all your bandwidth? Perhaps you just want to ban a user from a certain IP address? In this article, I'll show you how to use .htaccess to do all of that and more!

Identifying bad bots

So you've noticed a certain user-agent keeps showing up in your logs, but you're not sure what it is, or if you want to ban it? There's a few ways to find out:

• Google it: Try a search like this.
• Check the User Agent Database.
• Head over to Webmaster World and search again or start a new thread.

Once you've determined that the bot is something you want to block, the next step is to add it to your .htaccess file.

Blocking bots with .htaccess

This example, and all of the following examples, can be placed at the bottom of your .htaccess file. If you don't already have a file called .htaccess in your site's root directory, you can create a new one.

   #get rid of the bad bot   RewriteEngine on   RewriteCond %{HTTP_USER_AGENT} ^BadBot   RewriteRule ^(.*)$ http://go.away/

So, what does this code do? It's simple: the above lines tell your webserver to check for any bot whose user-agent string starts with "BadBot". When it sees a bot that matches, it redirects them to a non-existent site called "go.away".

Now, that's great to start with, but what if you want to block more than one bot?

   #get rid of bad bots   RewriteEngine on   RewriteCond %{HTTP_USER_AGENT} ^BadBot [OR]   RewriteCond %{HTTP_USER_AGENT} ^EvilScraper [OR]   RewriteCond %{HTTP_USER_AGENT} ^FakeUser   RewriteRule ^(.*)$ http://go.away/

The code above shows the same thing as before, but this time I'm blocking 3 different bots. Note the "[OR]" option after the first two bot names: this lets the server know there's more in the list.

Blocking Bandwidth Leeches

Say there's a certain forum that's always hotlinking your images, and it's eating up all your bandwidth. You could replace the image with something really gross, but in some countries that might get you sued! The best way to deal with this problem is simply to block the site, like so:

RewriteEngine onRewriteCond %{HTTP_REFERER} ^http://.*somebadforum\.com [NC]RewriteRule .* - [F] 

This code will return a 403 Forbidden error to anyone trying to hotlink your images on somebadforum.com. The end result: users on that site will see a broken image, and your bandwidth is no longer being stolen.

Here's the code for blocking more than one site:

RewriteEngine onRewriteCond %{HTTP_REFERER} ^http://.*somebadforum\.com [NC,OR]RewriteCond %{HTTP_REFERER} ^http://.*example\.com [NC,OR]RewriteCond %{HTTP_REFERER} ^http://.*lastexample\.com [NC]RewriteRule .* - [F] 

Banning An IP Address

Sometimes you just don't want a certain person (or bot) accessing your website at all. One simple way to block them is to ban their IP address:

order allow,denydeny from 192.168.44.201deny from 224.39.163.12deny from 172.16.7.92allow from all

The example above shows how to block 3 different IP addresses. Sometimes you might want to block a whole range of IP addresses:

order allow,denydeny from 192.168.deny from 10.0.0.allow from all

The above code will block any IP address starting with "192.168." or "10.0.0." from accessing your site.

Finally, here's the code to block any specific ISP from getting access:

order allow,denydeny from some-evil-isp.comdeny from subdomain.another-evil-isp.comallow from all