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
    7 Essential JavaScript Functions

    I remember the early days of JavaScript where you needed a simple function for just about everything because the browser vendors implemented features differently, and not just edge features, basic features, like addEventListener and attachEvent.  Times have changed but there are still a few functions each developer should...

  • By
    5 Ways that CSS and JavaScript Interact That You May Not Know About

    CSS and JavaScript:  the lines seemingly get blurred by each browser release.  They have always done a very different job but in the end they are both front-end technologies so they need do need to work closely.  We have our .js files and our .css, but...

Incredible Demos

  • By
    JavaScript Battery API

    Mozilla Aurora 11 was recently released with a bevy of new features. One of those great new features is their initial implementation of the Battery Status API. This simple API provides you information about the battery's current charge level, its...

  • By
    Create Digg URLs Using PHP

    Digg recently came out with a sweet new feature that allows users to create Tiny Digg URLs which show a Digg banner at the top allowing easy access to vote for the article from the page. While I love visiting Digg every once in a...

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.

  12. Jim

    Almost a full 10 years later and this post just really helped me out! Thanks!

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