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How to clear the AMP CDN Cache from Google Servers

Purpose of Google AMP Cache

The Google AMP Cache serves cached copies of valid AMP content published to the web. Serve content directly from the Google AMP Cache to provide a fast user experience.

The Google AMP Cache automatically requests the latest version of the AMP document from its origin and serves the updated version to the next user. That means that when you load the AMP Cache URL directly, that forces the cache to update, even without the more “urgent” update ping method.

Purge AMP CDN Cache

By using update-cache request it will update and remove the content from the Google AMP Cache. The content is updated within its max-age and crawl the fresh cache.

The update-cache the request requires the domain owner to sign the requests with an RSA key and to serve the matching public key from a standard URL on the origin domain.

How to Generate the RSA key

The OpenSSL project provides command-line tools to generate and manage asymmetric RSA keys. You can also generate RSA keys and manage them programmatically through the OpenSSL library, or an equivalent crypto API (node-crypto, NSS, or GnuTLS).

Generate a pair of RSA keys in the textual PEM format like this:

Post the public key on the domain to be refreshed at the following location:

The URL must be HTTPS. The key must be publicly accessible by Google.

Here are the steps :

  1. Download and Install Purge AMP CDN Cache extension.
  2. Upload and Activate
  3. Done! The Purge AMP CDN Cache will be visible on the AMP version of your site.

For more details how to upload extension click on this link  Upload and Install.

Note: Copy the private key and paste into entering private key section like below the screenshot.

Step 1: First go to WordPress Admin Area -> AMP option panel -> click on Purge AMP CDN Cache.

Step 2: Enter private key in this section.

Step 3: Click on the “submit” button.

How to Purge AMP CDN Cache in view Posts/Pages

Where you want to update the cache select posts/pages. Only it will be displayed on view posts/pages, For example, I am using posts like below the screenshot.

Step 1: Go to WordPress dashboard -> click on posts -> left-hand side Update AMP cache option is appear only on view post click on the “clear now” button like below the screenshot.

Step 2: Once you clear cache Green color check mark will be displayed on the left-hand side like below the screenshot.

That’s it for this tutorial!

We hope it helped you. If you have any feedback or questions, then please share them in the comments section below.

Ask your Questions Directly!
If you can't find the solutions in this article, then just ask us in the comments and we will answer it for you!
Updated on July 3, 2019

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  1. Hi,

    Thank you for this amazing plugin, but I have an issue: I can’t see this option on “Pages”. Is there another option to clear the AMP cache of a page?


    1. Hi Mireia,

      That option will be available in update AMPcache extension and that extension will be release soon.

    1. Hi johnlee,

      You have to run these two commands in your server to get the private key & public key

      1)openssl genrsa 2048 > private-key.pem
      2)openssl rsa -in private-key.pem -pubout >public-key.pem

      and if you have issue/problem then contact our technical team – they will help you as soon as possible.

    1. Hi Palla Sridhar,

      Yes you need to copy your public key and put inside “” file and make sure its readable format and if you have issue/problem then let us know.

  2. Hello there

    I can’t get this to work – the green tick never comes! As far as I know my general setup is right, with a bit of work I managed to manually clear the cache on one page using the same keys etc.

    Is there a way to debug the response?

    1. Hi Nick Scott,

      Could you please tell us how you manually clear the cache on one page using the same key.

      1. Hi there

        I followed the (really complicated) instructions on the Google site about how to do this manually – I understand you use the same process but automate it in the plugin.


    1. Hi Naresh,

      According to your requirement clear CDN page cache will send the request to google cdn for clear cache, CDN will clear it based on their queue after that, it will cache the latest content of your website page and still if you are facing issue/problem then contact our technical team - they will help you as soon as possible

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