> For the complete documentation index, see [llms.txt](https://docs.hedge.video/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.hedge.video/offshoot/features/duplicate-detect.md).
# Duplicate Detection
OffShoot will automatically detect duplicates when copying data into an existing folder structure. A file will not be copied when *all* of these conditions are met:
* A file with an identical name exists in the folder where the copy will end up
* That file has the same file size
* That file has the same modification date
When a file with an identical name already exists on the destination path, but has a different byte size and/or modification date, it will be copied using a counter following Finder and Explorer's duplicate naming conventions: `B002C006_180327_R1ZA.mov` becomes `B002C006_180327_R1ZA 2.mov`.
### Skip the modification date check
In some workflows, duplicate detection can’t rely on a file’s modification date. In that case, you can skip the modification date check.
{% tabs %}
{% tab title="macOS" %}
Requires **OffShoot 26.1.2** or newer.
1. Open Terminal.
2. Paste the command below, then press Return:
```
defaults write nl.syncfactory.Hedge.Mac SFIDefaultsSkipDuplicateDetectModificationDateCheck -bool true
```
To undo this change:
1. Open Terminal.
2. Paste the command below, then press Return:
```
defaults delete nl.syncfactory.Hedge.Mac SFIDefaultsSkipDuplicateDetectModificationDateCheck
```
{% endtab %}
{% tab title="Windows" %}
Requires **OffShoot 26.2** or newer.
1. Open PowerShell.
2. Paste the command below, then press Return:
```
New-Item -Path "HKCU:\Software\Hedge" -Force | Out-Null
New-ItemProperty `
-Path "HKCU:\Software\Hedge" `
-Name "SkipDuplicateDetectModificationDateCheck" `
-Value 1 `
-PropertyType DWord `
-Force
```
To undo this change:
1. Open PowerShell.
2. Paste the command below, then press Return:
```
Remove-ItemProperty `
-Path "HKCU:\Software\Hedge" `
-Name "SkipDuplicateDetectModificationDateCheck"
```
{% endtab %}
{% endtabs %}
#### Logging
Skipped files will be logged in the Transfer Log, under the section:
`-- Skipped files (already on destination) --`
Duplicates that do not match all criteria are logged as such:
`-- Transferred files --` \
`#1: B002C006_180327_R1ZA.mov`\
`path: XDROOT/CLIPS/B002C006_180327_R1ZA 2.mov`
#### Finding duplicates without copying
If an identical file exists in a different folder on your destination, the source file will be copied. If you are looking for a way to find duplicates on an existing drive, have a look at [Duplicate Detective](https://fiplab.com/apps/duplicate-detective-for-mac) or [Gemini](https://macpaw.com/gemini).
---
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