Oline mic test tool. Which is the best tool to use? Before using any mic testing tools you must be aware of their privacy statement. When you check your mic using the online mic test tool, almost every tool asks permission to access the microphone. It is mandatory for all websites according to browser policy. If any website doesn't ask you to access the mic and it directly starts the mic testing process then quickly bounces back from such sites. It can be harmful as they will record your audio and store it in their database. It is a great threat to your privacy. I will recommend you to use mictest.me to test mic online as I found it a trusted tool.