OISD is described as 'The blocklist prevents your devices from connecting to unwanted or harmful domains. It reduces ads, decreases the risk of malware, and enhances privacy' and is an website. There are nine alternatives to OISD, not only websites but also apps for a variety of platforms, including Self-Hosted, AdGuard, uBlock Origin and AdBlock apps. The best OISD alternative is Unified hosts file with base extensions, which is both free and Open Source. Other great sites and apps similar to OISD are FilterLists, Hagezi DNS Blocklists, 1Hosts and The Block List Project.