Trace quality is one of the essential requirements for analysis. Low quality traces may lead to complex, wrong conclusions for trace analysis. There are two main issues in trace quality. One is timing drift, which is when the actual event arrival time is earlier than the collected arrival time. The other is a missing event, such as when the tool cannot capture all the required events. Thus, proper tools shall be applied to guarantee the correctness of the traces. Both software tools and hardware devices are introduced in this chapter.