After generating a Resizer URL for an external image URL, there are cases where the Resizer URL continues to return a 5xx error. Since 5xx errors have a negative impact on SEO, we believe that a 4xx error should be returned instead.
For example, assume that the following Resizer URL was generated for the external image URL https://images.example.com/sample.jpg.
Resizer URL: https://www.example.com/resizer/v2/https%3A%2F%2Fimages.example.com%2Fsample.jpg?auth=dummy
The current behavior of the Resizer is as follows:
If https://images.example.com/sample.jpg returns a 403 error, the Resizer URL returns a 503 error.
If images.example.com becomes an invalid domain, the Resizer URL returns a 502 error.
As long as this situation continues, the number of 5xx image URL errors in Google Search Console will continue to increase indefinitely on our website.
Daiki Takahashi
