After enabling Alibaba Cloud CDN acceleration, some page elements fail to load because parameter filtering strips query strings before forwarding requests to the origin. Disable parameter filtering to restore access.
Symptom
After CDN acceleration is enabled for your domain, visitors report that certain elements—images, scripts, or other resources—fail to load. The domain worked correctly before CDN acceleration was applied.
Cause
Parameter filtering is enabled on your CDN domain. When active, CDN strips all query string parameters from URLs before forwarding requests to the origin server. For example:
A visitor requests:
https://example.com/image.jpg?version=2&size=largeCDN forwards to origin:
https://example.com/image.jpg
This affects caching behavior in two ways:
All requests for the same resource—regardless of query string parameters—are treated as identical and served from a single cached copy.
Resources that depend on query parameters to return different content (such as dynamically generated images or API-driven assets) receive incorrect or missing responses.
If your site uses URLs with parameters after a question mark (?), parameter filtering causes those requests to fail or return unexpected results.
Solution
Disable parameter filtering for the affected domain.
Log in to the Alibaba Cloud CDN console and click Domain Names in the left-side navigation pane.
Find the domain name you want to manage and click Manage in the Actions column. On the management page, disable parameter filtering.
Verify the fix
After disabling parameter filtering, confirm that element loading is restored:
Clear your browser cache and CDN cache for the affected domain.
Request a resource using a URL that includes query parameters.
Verify the correct content loads. If your origin returns different responses based on query parameters, confirm each variant is served correctly.
Best practices
Keep the following in mind to avoid similar problems:
Use consistent parameter order. CDN treats URLs with the same parameters in different orders as separate cache keys. For example,
image.jpg?color=red&size=largeandimage.jpg?size=large&color=redare cached as two different objects. Always list parameters in the same order—alphabetical order is a reliable convention.Use consistent parameter casing. Parameter names and values are case-sensitive in cache key matching. Use lowercase consistently across your URLs.
Review parameter filtering before enabling it. Parameter filtering is appropriate only for resources where query parameters do not affect the response—for example, tracking parameters appended to static asset URLs. Enabling it for dynamic or parameter-dependent resources causes this problem.