A method and computing device for delta compression techniques for reducing network resource transmission size are described. A first request for a network resource is received. The requested network resource is retrieved. A first response including the network resource is transmitted to the near end network optimizer. The retrieved network resource is stored as a first version of the network resource regardless of a directive that a cached version of the network resource is not to be used to respond to future HTTP requests for that network resource without successful revalidation with an origin server. A second request for the network resource is received. A most current version of the network resource is retrieved. A set of differences between the first version and the most current version of the network resource are determined. The set of differences are transmitted to the near end network optimizer.