Title: CAPTCHA cache issue
Last modified: August 30, 2016

---

# CAPTCHA cache issue

 *  [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/)
 * I posted previously that there was an issue with ZenCache caching the Really 
   Simple CAPTCHA images if the page was refreshed.
 * ZenCache have suggested a short-term workaround which does not work for me.
    `
   Add _wpcf7_is_ajax_call to your list of ZenCache URI Exclusions.`
 * The longer term suggestion is below:
    `The Contact Form 7 developer might want
   to consider using DONOTCACHEPAGE in their AJAX handler in order to prevent WordPress
   caching plugins from caching the response that is dynamic [the CAPTCHA image].
   Referencing: https://github.com/wp-plugins/contact-form-7/blob/master/includes/
   controller.php`
 * [https://wordpress.org/plugins/contact-form-7/](https://wordpress.org/plugins/contact-form-7/)

Viewing 14 replies - 1 through 14 (of 14 total)

 *  Plugin Author [Takayuki Miyoshi](https://wordpress.org/support/users/takayukister/)
 * (@takayukister)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319654)
 * Do you have this line in your wp-config.php file?
 *     ```
       define('WP_CACHE', TRUE);
       ```
   
 *  Thread Starter [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319680)
 * I just checked 11 wp-config.
 * Two which are dormant/test sites have the line you requested.
 *     ```
       <?php
       define('WP_CACHE', TRUE);
       ```
   
 * The other 9 which are the up-to-date sites do not have the line you requested.
 * Please advise if I need to add it in manually to all the wp-config files?
 *  Plugin Author [Takayuki Miyoshi](https://wordpress.org/support/users/takayukister/)
 * (@takayukister)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319681)
 * Normally ZenCache should have added it. Ask ZenCache author for support.
 *  Thread Starter [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319789)
 * Adding in
 *     ```
       <?php
       define('WP_CACHE', TRUE);
       ```
   
 * as the second line of the wp-config does not solve the caching of the CAPTCHA
   image on page refresh
 *  Thread Starter [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319805)
 * I might have a fix on this. I think this might be a FireFox issue.
 * See below
    I have enabled ZenCache on BajanThings. (BTW define(‘WP_CACHE’, TRUE);
   is added in on line 2 of wp-config.php once you enable ZenCache… if you disable
   it removes line 2)
 * Go to: [http://www.bajanthings.com/contact-burts/](http://www.bajanthings.com/contact-burts/)
 * * Open it in IE, I am using Version 11.0.9600.17842,
    press page reload and the
   CAPTCHA image refreshes as expected.
 * * Open it in Chrome, I am using Version 43.0.2357.132 m,
    press page reload and
   the CAPTCHA image refreshes as expected.
 * * Open it in Firefox, I am using Version 39.0,
    press page reload and the CAPTCHA
   image **DOES NOT** refreshes as expected. Are you seeing this too?
 *  Plugin Author [Takayuki Miyoshi](https://wordpress.org/support/users/takayukister/)
 * (@takayukister)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319825)
 * What other plugins do you use?
 *  Thread Starter [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319831)
 * Installed plugin on BajanThings are:
    Akismet Contact Form 7 Easy Theme and Plugin
   Upgrades FooBox HTML & Media Lightbox Google Analyticator Google XML Sitemaps
   Jetpack by WordPress.com NextGEN Gallery by Photocrati NextGEN Plus by Photocrati
   Really Simple CAPTCHA SEO Ultimate Simple Breaks Subscribe2 TablePress Weaver
   Show Posts Weaver Themes Shortcode Compatibility Weaver Xtreme Plus Weaver Xtreme
   Theme Support WP-DBManager WP-Optimize ZenCache
 *  Thread Starter [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319832)
 * Feedback from ZenCache after post about Firefox.
 * [@raamdev](https://wordpress.org/support/users/raamdev/) I see nothing ZenCache-
   specific here. This really seems to be two issues with CF7.
 *  Not setting DONOTCACHEPAGE on AJAX responses that deliver dynamic content.
    
   Not calling nocache_headers() on AJAX responses that deliver dynamic content.
 * Those are both educated guesses. I have not spent enough time with that plugin
   to say absolutely for sure. Further investigation on their part would be suggested.
 *  Thread Starter [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319833)
 * For what its worth I am using a win8.1 64 bit
 *  Plugin Author [Takayuki Miyoshi](https://wordpress.org/support/users/takayukister/)
 * (@takayukister)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319851)
 * No, they are not the direct cause of this issue. Maybe ZenCache isn’t related,
   either.
 * This is the HTML of the CAPTCHA image. I got this with the latest Firefox and
   Firebug.
 *     ```
       <img class="wpcf7-form-control wpcf7-captchac wpcf7-captcha-captcha-603" width="84" height="28" src="http://www.bajanthings.com/wp-content/uploads/wpcf7_captcha/1247228803.png" alt="captcha" srcset="http://i0.wp.com/www.bajanthings.com/wp-content/uploads/wpcf7_captcha/1310244177.png?zoom=2&resize=84%2C28" src-orig="http://i0.wp.com/www.bajanthings.com/wp-content/uploads/wpcf7_captcha/1310244177.png?resize=84%2C28" scale="2">
       ```
   
 * The “srcset”, “src-orig”, and “scale” attributes are not by Contact Form 7, they
   are actually added by something unknown. Something is changing the output of 
   Contact Form 7.
 * The “src” attribute is updated correctly by Contact Form 7, but “srcset” and “
   src-orig” are not. This is the direct cause of your issue.
 * You need to trace who is adding those problematic attributes. Try deactivating
   all other plugins and switching to the default theme. If this fixes the issue,
   then reactivate them one by one.
 *  Thread Starter [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [11 years ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319864)
 * Initially I thought it was Foobox….
 * Those parameters that you are referring to are added by the WP Jetpack Photon
   caching tool where WP caches your images and serve them from their super-fast
   network.
 * This is the CAPTCHA image with WP Jetpack Photon deactivated:
 *     ```
       <img class="wpcf7-form-control wpcf7-captchac wpcf7-captcha-captcha-603" width="84" height="28" src="http://www.bajanthings.com/wp-content/uploads/wpcf7_captcha/1662277107.png" alt="captcha" scale="0">
       ```
   
 * The WP Photon issue now makes sense now. I run another site that also uses your
   contact tool.
    [http://www.art-treasures-gallery.com/contact-art-treasures-gallery/](http://www.art-treasures-gallery.com/contact-art-treasures-gallery/)
 * I was struggling to work out why that contact form appeared to work and why all
   the others CAPTCHA images on my other sites were caching.
 * For Art Treasures Gallery I turned off Photon as the WP authors have been outspoken
   about free speech in China and China has hit back by blocking anything associated
   with WP servers, so to have the images on the Art Treasures Gallery website visible
   in China I had to uncouple all the tools that are linked to WP servers. For more
   info you can read about it here: [http://www.art-treasures-gallery.com/website/](http://www.art-treasures-gallery.com/website/)
 * What’s the next step?
 *  Thread Starter [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [10 years, 12 months ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319887)
 * [@takayuki](https://wordpress.org/support/users/takayuki/) Miyoshi just checking
   in to see where we go from here given issue appears to be WP Jetpack Photon
 *  Plugin Author [Takayuki Miyoshi](https://wordpress.org/support/users/takayukister/)
 * (@takayukister)
 * [10 years, 12 months ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319888)
 * Jetpack’s support?
 *  Thread Starter [Decimus](https://wordpress.org/support/users/decimus/)
 * (@decimus)
 * [10 years, 12 months ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319889)
 * [@takayuki](https://wordpress.org/support/users/takayuki/) Miyoshi this has been
   an issue for a while now for me and other. Think its time to move on and swap
   out to Fast Secure Contact Form which I’ve been testing and works out of the 
   box with Jetpack et al.

Viewing 14 replies - 1 through 14 (of 14 total)

The topic ‘CAPTCHA cache issue’ is closed to new replies.

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 * 14 replies
 * 2 participants
 * Last reply from: [Decimus](https://wordpress.org/support/users/decimus/)
 * Last activity: [10 years, 12 months ago](https://wordpress.org/support/topic/captcha-cache-issue/#post-6319889)
 * Status: not resolved