Image HMAC Settings

Version 17.3

This feature was introduced in Umbraco version 17.3. To use the settings on this page you will need this version or a subsequent version.

In Umbraco, image URLs have a HMAC value on the query string. This HMAC value is different by default across different sites, even when the image is the same. The Umbraco reccomendation is that the HMAC value is shared between sites.

e.g : /media/bzsfu4zz/profile-pic-2023.png?rmode=max&width=500&height=500&hmac=dee4e5904060c4ceb08081b30026abef0b59df51ff56803774831d253af58ade

By default, uSync won't change these values when you sync. However, we have a setting that can be turned on to update the HMAC to work on a different site with a different key. HMAC mapping is off by default in uSync and on by default in uSync.Exporter.

To turn it on or off go to appsettings and set MapHMACValues to true, or false.

 "uSync": {
  "Sets": {
    "Default": {
      "HandlerDefaults": {
        "Settings": {
          "MapHMACValues": false
        }
      }
    }
  }
}