Set the User Agent With PHP cURL

By  on  

A few months back, I shared with you how to download the contents of a URL and execute a HTTP POST transmission using PHP cURL. For security purposes, some hosts require that a common user agent be present in the POST. If an unacceptable user agent is given, the POST is ignored. Luckily, cURL allows us to "spoof" the server using any user agent we choose:

curl_setopt($ch,CURLOPT_USERAGENT,'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13');

A little sneaky but it could get you out of a jam at some point!

Recent Features

  • By
    5 Awesome New Mozilla Technologies You’ve Never Heard Of

    My trip to Mozilla Summit 2013 was incredible.  I've spent so much time focusing on my project that I had lost sight of all of the great work Mozillians were putting out.  MozSummit provided the perfect reminder of how brilliant my colleagues are and how much...

  • By
    How I Stopped WordPress Comment Spam

    I love almost every part of being a tech blogger:  learning, preaching, bantering, researching.  The one part about blogging that I absolutely loathe:  dealing with SPAM comments.  For the past two years, my blog has registered 8,000+ SPAM comments per day.  PER DAY.  Bloating my database...

Incredible Demos

  • By
    MooTools Window Object Dumping

    Ever want to see all of the information stored within the window property of your browser? Here's your chance. The XHTML We need a wrapper DIV that we'll consider a console. The CSS I like making this look like a command-line console. The MooTools JavaScript Depending on what you have loaded...

  • By
    Sexy Link Transformations with CSS

    I was recently visiting MooTools Developer Christoph Pojer's website and noticed a sexy link hover effect:  when you hover the link, the the link animates and tilts to the left or the right.  To enhance the effect, the background color of the link is...

Discussion

  1. Thanks for this tip. Was working on a project and found your tip very handy.

  2. Thanks for this! Was needed for a wikipedia curl request.

  3. Thanks for this, it for me too.

  4. hi..
    How to check whether a user agent string is supported by all the urls or not ? I have tried many urls with different user agent strings but I couldn’t find any user agent which is supported by all urls. When a user agent string is not supported, I get 0 (zero) as http response code and null as mime type. Please help.

  5. Thanks, without setting user agent I was getting this error:

    at nl.bitwalker.useragentutils.Browser.isInUserAgentString(Browser.java:154)

  6. Brilliand

    “for security purposes”… that’s incredibly weak security. I think it’s more common for the website to be doing useragent sniffing (to tailor the response to the browser), and simply not bothering to support uncommon useragents.

  7. perfect – thank for the tip!

  8. MJ

    Thank, that helped!

  9. i get error code like this. curl_setopt() expects parameter 1 to be resource, null given in /home/xxxx/xxxxx

  10. Try this…

    function scrap($url)	{
    	$curl = curl_init($url);
    
    	curl_setopt($curl, CURLOPT_USERAGENT, "My User Agent Name");
    	curl_setopt($curl, CURLOPT_FAILONERROR, true);
    	curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
    	curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    
    	$html = curl_exec($curl);
    	curl_close($curl);
    
    	return $html;
    }
    

    You are getting the error as curl_setopt() required first parameter as a resource returned by the curl_init($url);

  11. This, in fact, just got me out of a jam.

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!