Software to move thousands of files from many folders to one folder

Andrew,

Use File explorer search - search for *.json - see Search in File Explorer - TenForumsTutorials
In the results, press Ctrl+A to select them all.
Then drag them to the desired folder.

Denis

The most straightforward is to use file explorer as above. When doing so, I would suggest you copy, not move, in case something goes amiss, then delete afterwards.

If you want some other well-known options:

Teracopy:
TeraCopy for Windows - Code Sector

Robocopy perhaps- built in, and has been provided a GUI mentioned here:
Robocopy in Windows 10 & Microsoft Robocopy GUI

Robocopy: The Ultimate Guide (A Complete How-To)

This can be done with few commands, that can be put in .bat file.

Command is described here at superuser forums:
Make new text file and copy in it:

Code:

@echo off
md merged
for /f "delims=" %%f in ('dir /b /ad') do (
    if not %%f==merged xcopy "%%f"\*.json merged /s /y
)

save it and rename to something.bat. Put it in topmost folder of your files, and run

All of the above but not seen is don't worry about the drive space, Move shouldn't change what is available while Copy will take up more space, same for saving duplicates. Example of choices:

I vote with dalchina about Copy instead of Move. If something goes wrong, it might be hard or very hard to get the original files back. With Copy, one can compare the source with the target, after making sure byte-sizes match, then the source files can be deleted. Another idea: Copy in "clumps" -- perhaps no more than 50-100 files at a time. More control over the operation that way.

Maybe I'm missing something but I see absolutely no need to use a third party app to move files. A simple organize by file extension in explorer - jpeg, json and click the files with the extensions to move or copy. Don't need a third party app for that.