Information will be displayed after you've selected a KV.
This tool does not store the uploaded KV on our servers. It is temporarily stored in memory so that we can read through it in order to display pertinent information to you, the user.

So be at ease! Your KV is safe.
This tool is not able to display information about ALL KV files. Some of them will show up as invalid, or the information read from the KV may be incorrect. If that is the case, please try checking your KV in another info tool to make sure that the file is actually valid.