If you have just installed the CDN Sync Tool plugin into your WordPress site, you may have a question on how to sync your files with your Amazon S3 account when completing a post or a page.  This article does not get into how to perform the initial setup of the CDN Sync Tool.

When using the CDN application within WP Super Cache plugin, you can specify with which directories you want to use the CDN capabilities.  By default, it will be set to sync the  wp-content and wp-includes directories. This works just fine, and you can add additional directories if you wish.

As for updating post / page content, and then syncing those media files, you typically only have to be concerned with items in the wp-content directory because this is where all images, PDF documents, and other media is stored when uploaded through the WordPress media manager. 

If you put up a new post or page that contains no images or other media, then you shouldn’t have to be concerned with any CDN sync updates. 

If in fact your new post/page contains images, follow these directions to synch with Amazon S3 CDN.  Again, this is not a an article covering initial configuration – we are staying within the scope of updating site content.

Step 1

When you are finished with your post(s) or page(s), you will want to sync your files with Amazon S3.  To do so, click the CDN Sync Tool button at the top of the page (disregard the dropdown options).

Syncing your WordPress media with the CDN Sync Tool


Step 2

You will now be on the CDN Sync Tool interface.  There are a lot of options here, but you can disregard all of these except for the Sync Files widget.  By default, all directory options are checked (Media Files, Theme Files, etc). 

The “Don’t skip if already synched” option is unchecked.  When unchecked, the sync process will NOT overwrite existing files on the S3 server.  This simply makes the synching process faster.  Checking this box will overwrite all files (from the selected options just above).  There is usually no problem if you were to overwrite things.  It just takes a while.

Back to what directory check boxes to select. You have a few options, but I will generally do one of two things.

Recommended Option: Leave all items checked. I will UNCHECK (or leave unchecked) the “Don’t skip if already synced” option.  By doing this, you are making sure you sync any new plugin files, CSS style sheets, and other items that may have been automatically installed.

Option 2: Select only Media Files. If you simply want to sync only  the new media files that you used in your post (i.e. images, PDF document, etc.), then you can uncheck ALL options except for the “Media Library” option. 

When ready, click the blue “Sync Files” button.  The syncing process begins.

CDN Sync Tool step 2


Maintenance Recommendation:  It is advisable to occasionally CHECK the “Don’t Skip if Already Synced” option.  This will keep your CDN file set updated with WordPress updates, plugin updates, theme updates, etc.  Do this every 2-3 weeks or after any major WordPress update.

Step 3

Just kick back and wait until you see the list of files that have been uploaded and/or skipped.  If you see a list of files that have been skipped, this is normal.  This relates to the “Don’t skip if already synced” option mentioned in step 2 above.   Again, this option is by default unchecked and if left that way when synching then you will see the list of files that were skipped because they already exist on the S3 server. An illustration of what you will see when synching has completed is below.

Wait for indication that your files have been synced or skipped


Step 4

Syncing is done!  Now it’s time to clear your cached files to ensure your visitors see the latest updates.

Related to the CDN Sync Tool plugin is a plugin called WP Super Cache.  This WP Super Cache plugin creates cached files to give your web visitors.  Serving cached files saves on loading time and server resources.  The cache will rebuild itself regularly – but if you don’t manually clear it when making changes to the website, visitors might not see your new changes right away.

Clearing the cache is easy.  Just click on the “Delete Cache” button at the top of the page.  It’s right next to the CDN Sync Tool button.  The cache will later rebuild itself, so your job is now done. See the image below.

Delete your cache files



  • See the CDN Sync Tool in the WordPress extensions directory.
  • See the WP Super Cache plugin in the WordPress extensions directory (A highly recommended plugin)
WordPress Plugin Help How to Sync Using the CDN Sync Tool When Finishing a Post or Page in WordPress.