URL filtering is an essential tool used by Internet Service Providers (ISPs) and organizations to restrain clients from accessing non-secured or illegal web content. Designing a URL filtering method that achieves a high bit rate of 100 Gb/s and beyond for international ISPs is a challenging task. High-performance URL filtering with multi-gigabit rate capacity requires a fast URL matching algorithm and an enhanced packet processing technique. In this paper, we tackle these challenges by design and development of a software-based URL filtering system to support 100 Gb/s bandwidth. Our aim is to build a system that runs on a single commercial off-the-shelf (COTS) server with multi-core CPUs. We propose a compact URL representation using AVL tree and a multi-core/multi-thread filtering technique with session hijacking and fast packet processing framework. Performance measurements results show successful URL filtering operating at 100 Gb/s in a real network testbed.