However, if you exceed this free opportunity, you need to pay for the test. In addition, there are differences between different duplicate checking systems, such as HowNet and VIP, which can be tested indefinitely as long as they pay.
It should be noted that although some so-called "free duplicate checking" websites may provide seemingly free opportunities, these websites often charge fees without users' knowledge or provide inaccurate duplicate checking results. Therefore, when choosing a duplicate checking system, it is suggested to choose a regular and reputable duplicate checking system to avoid unnecessary losses.