Processing

Process marked… opens the four-step screen that actually changes your disk: Choose → Configure → Process → Done. There are five actions and they differ enormously in what they leave you. Pick before you read the steps.

The five actions

Full detail on reversibility is in What can be undone, and what cannot.

Choose (step 1)

"What should we do with them?" — with the reassurance that "Nothing is committed yet — you'll confirm on the next step." The line above reads "Step 1 of 4 · N files marked · X reclaimable".

Two warnings can appear here:

• "N group(s) would lose every copy" — you have ticked every copy of something.
• "Includes N files you ticked inside protected folders — they will be removed too." A folder shield stops Trawler ticking files, not you.

Replace with hardlink is greyed out until you turn it on in Settings → Safety & protection ("Allow Replace with hardlink"). Enabling it takes effect the next time you open this screen — no restart.

Configure (step 2), per action

Archive to ZIP

Pick a Destination folder with Change…, then a Compression:

Solid stores each set of identical copies once, so it is dramatically smaller when you are archiving duplicates. The cost: double-clicking it will not open it. You need 7-Zip or WinRAR — or Trawler's own Restore, which reads both formats.

Split size splits the archive to fit removable media: Single archive (no split), CD (700 MB), DVD (4.7 GB), DVD-DL (8.5 GB), Blu-ray (25 GB), BD-DL (50 GB), BD-XL (100 GB), Custom…. Custom… has no size field and behaves as a single archive.

Archives are named for the moment they were written — archive-20260801-143512.zip — and split parts add a number: archive-20260801-143512-(1).zip, -(2), and so on. The Solid format uses .tar.zst in place of .zip.

Each part is written, flushed to disk, and only then are that part's originals deleted. If the flush fails, the originals stay.

Settings → Archive defaults sets what this screen starts on — compression, split size and the folder to archive into. Change them here for one run without touching the defaults; the defaults are updated when a run starts, so the choice you actually used is the one that comes back next time.

Move to Recycle Bin

"Marked files go to the Windows Recycle Bin. You can recover them from there until you empty it."

You must tick "I understand some files may skip the Recycle Bin and be gone for good." before Start becomes available. Windows sends some files straight past the Recycle Bin — anything too large for it, and most files on network locations — so recycling is not a guarantee you can get them back. Turn the tick off for every action in Settings → Safety & protection.

Delete permanently

"This permanently deletes the marked files. Files are removed from disk and cannot be recovered from the Recycle Bin."

You must tick "I understand these files cannot be recovered." before Delete permanently becomes available. That confirmation comes from Confirm before destructive actions in Settings → Safety & protection, which is on by default. Move to Recycle Bin and Replace with hardlink ask too, each with wording that matches what it does; switching action clears the tick.

If your selection reaches into a protected path, all five actions say so before you start — and then run. See Choosing what to remove.

Move to another location

"Files are moved, not copied. Marked files are relocated to the destination, preserving their folder structure. Nothing is deleted; the source drive gains the freed space."

Structure is preserved beneath each folder you ticked: tick D:\Stuff\Pictures, move to F:\Backup, and D:\Stuff\Pictures\2024\img.jpg lands at F:\Backup\Pictures\2024\img.jpg.

Trawler checks the destination has room and tells you either "…free at destination · … to move — fits." or "— may not fit." That is information, not a barrier — a shortfall does not stop you starting.

A move to a folder inside the area you scanned (or a scan of a folder inside the destination) is refused outright, before anything is touched.

Moving across drives is a copy followed by a delete of the original, so it takes as long as copying does. Moving within one drive is near-instant.

The record Trawler leaves behind is a file called .trawler-moves.json in the destination folder. Keep it and Restore can send everything back; delete it and it can't.

Replace with hardlink

"Each duplicate becomes a second name for the kept file. Deleting one name leaves the data intact, but there is no separate copy to restore." Editing one edits all of them, because there is only one copy of the data.

Trawler checks eligibility first — "Checking which files can be linked…" — then reports "N group(s) · N file(s) can be linked · N skipped". Groups are skipped when:

• the copies sit on different drives — linking only works within one drive;
• the drive can't do it (not a local fixed NTFS drive — network shares and removable drives are out);
• every copy in the group is ticked, leaving nothing to link to;
• the copies were matched by name and size only, never confirmed as identical contents. Run Verify exact copies on the Duplicates tab first if you want those included.

A protected path is not one of these reasons. A copy you ticked inside one is linked like any other; you are told about it beforehand, on the screen where you choose the action.

Process (step 3) and Done (step 4)

"Step 3 of 4 · You can keep working — this runs in the background." Run in background closes the screen and leaves the job running; come back to it any time.

Cancel stops between files. The button changes to "Cancelling…". Files already handled stay handled and the rest are untouched.

For an archive, what counts as "already handled" depends on Split size:

The "… reclaimed." figure on the Done screen counts only the finished parts. Get those files back the same way as any archive — see Restore from an archive.

One file failing does not stop the run. The Errors tile counts them and reads "see scan log"; the per-file list is in Scan report → Scan errors with the stage filter set to File actions. That record persists.

A file that was skipped is not a failure, and Done counts it separately. The Skipped tile covers marked files the action never touched, so processed, skipped and errors always add up to the number you marked — nothing marked goes unaccounted for. Of the five actions, only Replace with hardlink leaves anything skipped. Its reasons are listed underneath, counted in groups rather than files:

Near the end the progress bar goes indeterminate and the caption reads "Recalculating folder sizes. On a large drive this can take a moment." Nothing is wrong — this is the longest silent stretch of a big job.

Done reports how much was reclaimed, how many files, where the archive went if you made one, and a breakdown under "Where the space went".

Clearing empty folders

After a successful Archive, Recycle, Delete or Move, Trawler sweeps up the folders that emptied — you'll see "Removing empty folders · N removed". Replace with hardlink doesn't trigger it, because it leaves every file where it was.

• Empty means empty — zero files, zero subfolders. A folder holding a single stray file stays.
• It walks upward: remove a folder and its parent is tested next, and so on.
• It never removes a folder you scanned, and never removes a protected path.
• A folder it can't remove stops that branch and is reported; the rest of the sweep continues.

On the free version

All five actions are Pro. You can choose an action and configure it, but pressing the final button raises "Unlock the full version" rather than starting — "Process marked files" is a Pro feature. Nothing is written first.

Related

• What can be undone, and what cannot — read this before Delete or hardlink
• Choosing what to remove — ticks and protected paths
• Restoring from an archive
• Recovering an interrupted hardlink job