Systems and techniques are described for caching resources. Multiple distinct resource identifiers that correspond to the same resource can be automatically collected, wherein the multiple distinct resource identifiers are included in resource requests that are sent from at least one client to at least one server. Next, a key can be automatically determined that matches the multiple distinct resource identifiers by analyzing the multiple distinct resource identifiers. A resource request can be received from a client that includes a resource identifier, and in response to determining that the resource identifier matches the key, the resource can be sent to the client.