Adapt for slow connections

Adjust the quality of images on your site based on the end user’s connection quality.

When Image and Video Manager detects a slow connection you can automatically deliver optimized images to reduce the impact of the poor network quality. To ensure a great web experience for all your users Image and Video Manager only delivers images with a reduced file size when a slow connection is detected. Users on standard network connections continue to receive the original image.

Create an Image and Video Manager policy and go to Image and Quality Settings>Derivative Quality>Quality Value Override for Slow Connections to set a fixed quality value for users with slow connections.

Here's the image, delivered to users on a standard connection:
Image Image optimization details Value
Original file size 3100 KB
Transformed file size 148.0 KB
% Byte change ↓ 95.3%
Encoding quality 84

Here's the same image, optimized for a user on a slow connection:

You can use Piez, a Google Chrome extension, to view the optimizations made by your Image and Video Manager policies. To learn how to use Piez you can read this blog post.

Here's a summary of the information available in Piez about the optimizations applied to this image.
Image optimization details Value
Original size 3100 KB
Transformed image size 148.0 KB
% Byte Change ↓ 98%
Encoding Quality 50

Note that the image sent to the user on the slow connection is smaller in file size and has a lower encoding quality. A lower encoding quality means that the image has a lower visual fidelity. The encoding quality of 50 was set in the policy. You can set the encoding quality to a number between one and 100 when you create your own policy.

How to

  1. Go to > CDN > Image and Video Manager.
  2. Select a contract and a policy set name, then click Manage Policies.
  3. Click Add New Policy.
    The Name Your Policy window appears:
  4. Enter Adjust_Quality_for_Slow_Connections in the Policy Name field and click OK.
    The Image Policy Editor appears:
  5. Select Derivative Quality from the Image and Quality Settings.
  6. Select the Static from the Quality Type.
    Note: The Quality Value Override for Slow Connections field is available for both Perceptual and Static quality settings.
  7. Enable the Quality Value Override for Slow Connections field.
  8. Set the Quality Value Override for Slow Connections field to a fixed value of 50. Only users accessing images with a slow connection will see images displayed using this setting.
  9. Save and test your policy on staging and then push it to production when it's ready.
    To validate the impact of your policy and even view before and after images use the Piez Google Chrome extension. You can learn how to use Piez by reading this blog post.

Next steps

For more information about optimizing images, see the Image and Video Manager Help.