Overview

There are several reasons why errors could appear when trying to render your image. These are classified as both mild and severe errors. Mild errors are any 4xx level error (issues related to your origin) while severe errors are any 5xx errors (issues related to the network/imgix).

The documentation here goes over what causes 4xx and 5xx error codes.

You can check on the count of these errors by going to your Analytics tab in your Dashboard and going to the Rendering tab. At the bottom, you will see sections for both mild and severe render errors.

How Errors are Calculated

Errors are only recorded once the origin image has been successfully requested. If the origin image has not yet been successfully requested, errors will not be counted, as seen in your Analytics section of your dashboard. 

For example:

1. Your origin image, which has not been accessed yet.
2. You add a link to your image, using invalid parameters such as: http://vuaws.imgix.net/image01.jpg?w=0
3. The image returns a 404 error, but it is not logged in your error report.
4. Someone accesses your image successfully using valid parameters at http://vuaws.imgix.net/image01.jpg?w=300.
5. Someone accesses your previous image with the invalid parameters at http://vuaws.imgix.net/image01.jpg?w=0, resulting in a count of one error.

If the origin image has not yet been accessed successfully, we treat the image as if it did not exist. This is to prevent non-sensical errors from appearing in the report.