How do I manage and compare saved SizeTrend scans?

Save a scan you may want to compare later

After a scan finishes, open Filter | Compared to scan... and click Save current scan.... Give important baselines a recognizable name, such as Before server upgrade or Month end, rather than relying only on the date.

Creating a local saved scan remains available in SizeTrend Free. Loading a saved scan for comparison is available during the first 14 days and with a Professional license. Free can also use one What Changed comparison when a compatible automatic snapshot is available.

Compare the current scan with an earlier one

Scan the same drive or folder again, open Filter | Compared to scan..., and choose the earlier result under Previously Saved Scans. SizeTrend shows the changes between the compatible scan roots instead of making you compare two folder trees by eye.

A comparison is most useful when both scans cover the same location. If a saved scan is partial, incomplete, from another drive, or covers a different folder, read its properties before drawing conclusions from missing paths or smaller totals.

Open Manage Saved Scans

From Compared to scan..., open Previously Saved Scans and click Manage saved scans.... The window lists each scan's name, creation time, scanned location, type, and file size.

Open loads the selected scan. Show in Explorer selects its file, Rename changes its display name, and Properties shows details such as the scan type, flags, format version, and base-scan relationship.

Understand manual, automatic, and scheduled results

Manual scans are the baselines you save yourself. Automatic snapshots can be created after eligible whole-drive scans, no more than once per day, and SizeTrend normally retains the latest two for each drive. Scheduled results come from the Windows Task Scheduler definitions created under Scan | Schedules.

A result can be a full scan or a smaller delta that depends on a full base scan. It may also be marked partial or incomplete when some folders could not be read. Use Properties when a result's role is not obvious.

Delete history through SizeTrend

Select one or more unwanted results and click Delete. If a selected item is a full base scan required by later deltas, SizeTrend adds those dependent scans to the confirmation because they cannot be opened without the base. Delete All also removes dependent deltas before their full bases.

This dependency check is why deleting scan files directly in Explorer is a poor shortcut. A remaining delta cannot be opened without its base. The manager also coordinates with a scheduled scan that may be publishing a new result at the same time.

Deleting a scheduled result here removes that result, not its Windows Task Scheduler definition. Removing the schedule itself is a separate destructive operation under Scan | Schedules, and it permanently deletes all results owned by the selected schedule.

Control automatic history

The checkbox at the bottom of Manage Saved Scans controls whether eligible whole-drive scans create automatic snapshots. The storage summary shows how much space those snapshots use. Turn the option off if you do not want automatic history, or leave it on if the quick What Changed baseline is valuable.

Automatic snapshots are skipped when the scan is incomplete, empty, not a whole local volume, too recent, or when saving one would leave too little free space. A missing automatic snapshot therefore does not necessarily mean the scan itself failed.