FastCopyFastCopy complete tutorial: from install to your first copy
1Download and install from the official site
Get the latest 64-bit build from fastcopy.jp. Both an installer and a portable zip exist; the portable version keeps settings in an INI file next to the executable. During install you can optionally add FastCopy to the Explorer right-click menu.
2Understand the main window
Source is what you copy, DestDir is where it goes. The four big mode buttons decide how existing files are treated: Diff (No Overwrite) skips files that already exist, Diff (Size/Date) overwrites only when size or timestamp differs, Diff (Newer) copies when the source is newer, and Copy (Overwrite) replaces everything unconditionally.
3Pick the right mode for the job
For backups onto a mostly identical destination, Diff (Size/Date) is the safe default — it re-copies only what changed. Use Copy (Overwrite) only when you want the destination to become an exact mirror, and beware that it will overwrite newer files.
4Start the copy and read the log
Press the top Execute button. The result dialog shows total time, throughput and a per-file error list — anything highlighted red needs attention. Enable Log in the option menu to keep a history you can reopen later.
5Verify critical copies
For backups you cannot afford to lose, enable Verify in the settings so FastCopy re-reads the written data and compares it (MD5/SHA/xxHash). Verification roughly doubles I/O but guarantees the copy is byte-identical.
Frequently asked
QIs FastCopy really faster than Windows Explorer?
For many small files and for same-drive copies, yes — usually 1.5x to 4x. Explorer copies sequentially and checks more per file; FastCopy uses multi-threaded reads and writes and can overlap them.
QDo I need administrator rights?
Not for normal copies. Run as administrator only when copying protected system folders, or when you want pre-allocated space on the destination for maximum NVMe throughput.
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