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
    CSS vs. JS Animation: Which is Faster?

    How is it possible that JavaScript-based animation has secretly always been as fast — or faster — than CSS transitions? And, how is it possible that Adobe and Google consistently release media-rich mobile sites that rival the performance of native apps? This article serves as a point-by-point...

  • By
    Write Better JavaScript with Promises

    You've probably heard the talk around the water cooler about how promises are the future. All of the cool kids are using them, but you don't see what makes them so special. Can't you just use a callback? What's the big deal? In this article, we'll...

Incredible Demos

  • By
    External Site Link Favorite Icons Using MooTools and CSS

    I recently came upon an interesting jQuery article about how you can retrieve all external links within a page, build the address of the site's favorite icon, and place the favorite icon along side the link. I've chosen a different approach which...

  • By
    MooTools ContextMenu Plugin

    ContextMenu is a highly customizable, compact context menu script written with CSS, XHTML, and the MooTools JavaScript framework. ContextMenu allows you to offer stylish, functional context menus on your website. The XHTML Menu Use a list of menu items with one link per item. The...

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!