Uniform resource locator (URL) filtering is a fundamental technology for intrusion detection, HTTP proxies, content distribution networks, content-centric networks, and many other application areas. Some applications adopt URL filtering to protect user privacy from malicious or insecure websites. AdBlock Plus is an example of a URL-filtering application, which filters sites that intend to steal sensitive information. Unfortunately, AdBlock Plus is implemented inefficiently, resulting in a slow application that consumes much memory. Although it provides a domain-specific language (DSL) to represent URLs, it internally uses regular expressions and does not take advantage of the benefits of the DSL. In addition, the number of filter rules become large, which makes matters worse. In this paper, we propose the fast uniform resource identifier-specific filter, which is a domain-specific pseudo-machine for the DSL, to improve the performance of AdBlock Plus. Compared with a conventional implementation that internally adopts regular expressions, our proof-of-concept implementation is fast and small memory footprint.