Tips & How To's

Modern Mobile Redirect Using .htaccess

The following set of rewrite rules will redirect all Android, Blackberry, iOS, Windows and WebOS devices to a specific mobile directory on your website. Additionally, it will redirect Google’s mobile crawler – according to Google search spam czar Matt Cutts this is perfectly acceptable and even somewhat encourage.

To implement these rules:

  1. Replace “mobiledirectoryhere” with the path to your mobile site. If your mobile site is located in a subdirectory, use the full URL (including “http://”) and you can omit the first RewriteCond.
  2. Then copy & paste the ruleset into the site’s .htaccess file or the main apache configuration.


Since the last time I wrote about mobile browser detection and redirection in 2009 the mobile device landscape has changed once again. Smartphones dominate the mobile browsing landscape and feature phones are almost not existant in server logs.

The old redirection rules I posted attempt to redirect every mobile phone under the sun. At this point in 2011, it’s probably safe to completely ignore ancient phones and simplify your Apache rules in the process.

Tips & How To's

How To Detect Mobile Visitors Using .htaccess Rewrite Rules, Simplified

Since my original posts on mobile redirection in .htaccess files I’ve gotten some comments and emails asking for step-by-step guidance on exactly how to “install” these rules. I hope this post will answer some of those questions.

Before you continue reading, if you have php installed on your server, you may want to consider Andy Moore’s php based detection solution.

The Basics

First off, some basic requirements. You’ll need:

  • Apache/Linux Hosting. Microsoft’s IIS has a completely different method for handling this sort of thing.
  • FTP access.
  • Apache mod_rewrite enabled. Depending on the type of hosting you have, it may be difficult to determine if you have this module installed and it may be impossible to enable if you don’t. If the steps below simply don’t seem to work, there is a good chance you don’t have mod_rewrite installed. Ask your tech support.
  • Mobile site in a subdirectory, eg. This set of rules I’ve posted will not work with a mobile subdomain.

The Steps

  1. Download mobilerules2.1.txt.
  2. Open the file in your favorite text editor, replace the 2 instances of “mobiledirectoryhere” (without quotes) with the directory name you are using for your mobile site. Save it.
  3. Open FTP client, enable ‘view hidden files’ – files beginning with a dot are hidden on linux. This option is typically buried in a “view” menu or something to that effect. Results may vary.
  4. Navigate to your site’s webroot (probably ‘htdocs’ or ‘www’).
    • If there is already a .htaccess file present in the directory. Download it, open it in your favorite text editor. Copy & paste the contents ofmobilerules2.1.txt into the file. Save it, upload it.
    • If there is no .htaccess file present. Upload mobilerules2.1.txt as is, rename it to .htaccess.
  5. Your Done. Test it from a mobile device.

If you have any questions please leave a comment.

Note: This script treats all opera mini, iphone and android the same as other phones and browsers. Leave some comments if you’d like me to address this.

Web Development


To scale at Digg they followed a set of practices very similar to those used at eBay. No joins, no foreign key constraints (to scale writes), primary key look-ups only, limited range queries, and joins were done in memory. When implementing the comment feature a 4,000 percent increase in performance was created by sorting in PHP instead of MySQL. All this effort required to make a relational database scale basically meant you were using a non-relational database anyway. So why not just use a non-relational database from the start?

[via High Scalability]

Tips & How To's

How To: Exclude Words Like “An, A, The” From Alphabetized MySQL ORDER

When ordering lists of names or titles it’s sometimes desirable to exclude articles or other words from the order clause (eg. you want “The Burning Hell” to show up before “Great Lake Swimmers” in a list ordered by name). Early on in my career I must have assumed it was not possible and never bothered to look into again because I don’t recall ever ordering a list like this.
Anyways. Here’s how you do it:


[thanks metafilter]<


Even Google Makes Mistakes

This is an expert from a Gmail Blog Post re: the recent gmail outage:

Unexpected side effects of some new code that tries to keep data geographically close to its owner caused another data center in Europe to become overloaded, and that caused cascading problems from one data center to another. It took us about an hour to get it all back under control.

This sounds exactly like the types of bugs I create. The fact that Google makes these sorts of mistakes, even though they do a lot more testing and have bigger teams, etc; makes me feel good about my programming skills.