BlockCheck

BlockCheck is a Russian ISP blocking-type checker created to identify how websites from Russia’s prohibited-information registry were being blocked by internet providers. The tool was designed for a specific network environment and is explicitly not useful outside Russia. It runs tests that help distinguish different blocking methods, such as DNS manipulation, IP blocking, HTTP blocking, TCP reset behavior, and deeper filtering patterns. The repository is now archived and marked as not currently working, so it should be treated as a historical and diagnostic reference rather than a maintained utility. Its value is strongest for people studying network censorship, ISP filtering behavior, and the technical mechanics of access restriction. Because test results could be affected by circumvention tools, the project warns users not to run it while bypass systems are enabled.