Configuring SmartVision Image Transcoding with the Performance & Delivery Rule Builder


The rule builder only works with the V2 config framework. If you see the text "configuration is not supported" on the Performance & Delivery Rules screen, you will need to have Instart migrate your configuration format. Please contact your account executive to initiate this migration. If you have the V1 configuration format, you will continue to have limited self-service control over your caching policy and over performance features JavaScript Streaming, Image Transcoding, and Brotli Compression until your configuration is updated. Refer to Delivery and Performance Configuration Overview for details.

This document describes how to use the Performance & Delivery Rules builder to create rules to control the SmartVision Image Transcoding feature. For general information about the Performance & Delivery Rules screen, see the document Configuring Performance & Delivery Rules in the Portal. For a detailed description of Image Transcoding, see What is Image Transcoding?

In the rule builder screen, select criteria you want to use to decide to turn Image Transcoding on or off. For example, here we are using a wildcard match for *.jpg or *.png on the request path:

Then choose SmartVision Transcoding as an action. This exposes the available configuration settings you can apply to the feature.

You can turn it On or Off if the chosen criteria match.

If On, transcoding can be individually disabled for either JPGs or PNGs with the checkbox on the left.

Next is a slider that allows you to choose the profile for how the transcoding feature is applied to images. The choices are

  • Inherited: inherits the value this has been set to previously.
  • Lossless: with this setting images will not lose any quality and the file size benefit of Image Transcoding is minimal
  • Safe: sets the safe quality profile for SmartVision. Choosing this or either of the next two profiles offers a tradeoff between the size of the transcoded images and the quality of experience. This value to used when a customer wants to have minimal impact to image quality, but results in a smaller byte reduction
  • Standard: this is middle ground between safe and aggressive. This results in a small impact to quality with a better chance of byte reduction. This is the default value.
  • Aggressive: this results in a maximal byte reduction but will potentially have a visible impact on image quality for some images.
  • Manual: this allows you to override SmartVision with a single quality level that will be applied in transcoding all JPG and PNG images.


Setting the Profile has no effect on transcoding PNGs to PNG.

Output to allows you to decide to encode to the same format as the original image, or to Advanced Image Formats, which transcodes JPG and PNG images to WebP or JPEG XR images when the requesting browser is Google Chrome (for WebP) or Microsoft Internet Explorer 10.0 and above or Microsoft Edge (for JPEG XR).