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PDF Deduplicator

by CCsouljump · github.com/CCsouljump/zotero-pdf-deduplicator

Detects duplicate PDF attachments that are byte-identical by SHA-256 hash and moves the extra copy to the trash after you confirm.

PDF Deduplicator has Atlas grade A (recommended) because every code check came out low. It works with Zotero 9–10. Last checked 6 Nov 2026.

Files, sync & backupOrganising & tags
View source
Downloads a .xpi file (0.01 MB). In Zotero, open Tools → Plugins and install it from the file.
In useAn estimate of how many copies of Zotero have it: Zotero downloads each new version once for every copy that has the plugin, so we count the downloads of its most-downloaded recent release. Rounded. Plugins that update from outside GitHub count low.
9
DownloadsAll-time downloads of its release files from GitHub, counting every update. Installs from elsewhere aren't counted.
9
ReleasesVersions published on GitHub. Everyone who has the plugin downloads each one again, which adds up in Downloads.
1
StarsPeople who starred the repository on GitHub: a rough measure of interest.
0
ContributorsPeople who have committed code to the repository.
2
LicenceThe licence the code is published under, as GitHub reports it.
MIT
A
Atlas gradeRecommended
because every code check came out low
Applies to v1.3.0, released 12 Oct 2026Code checked · not yet tested in a live Zotero
Another plugin uses the same IDOne other plugin shares this add-on ID. Zotero can only install one of them.
What we found in the codeSets the gradeThe worst finding in these three areas sets the grade.
Code transparencyReadable code; not yet checked against the published sourceThe developer uploaded the release file from the CCsouljump account. We haven't yet checked whether this file matches the public source code.UnknownWe couldn't check this yet.
Updates
Updates come from this project's GitHub repositoryThe update address offers this version
Where your data goesNo web requests foundLowLow concern: normal for plugins that do this job. Listed so you know.
No further detail for this area yet.
Powerful capabilitiesWorks with files on your computerLowLow concern: normal for plugins that do this job. Listed so you know.
Low concern (1)
Works with files on your computer
Before you installShown, not gradedFacts to help you decide. They don't change the grade.
Works withZotero 9, 10 · not 11 betaUpdates automatically
Zotero 9 ✓ worksZotero 10 ✓ worksZotero 11 beta ✗ doesn't work
What you'll needNothing extra detectedDetected automatically from its code
No further detail for this area yet.
MaintenanceActive · last release 12 Oct 20262 contributors
No further detail for this area yet.
LanguagesDocumentation in EnglishInterface language not declared
No further detail for this area yet.
We report what we found in the code. Open any area for the evidence.How we gradeReport a problem

What it does

Written by AI from the README

Detects duplicate PDF attachments that are byte-identical by SHA-256 hash and moves the extra copy to the trash after you confirm. Checks new PDFs as they arrive and scans older ones from Tools, Scan Existing PDFs.

Zotero's duplicate pane compares metadata, not files, so the same PDF can sit in a library many times. This finds true file duplicates only; re-saved or OCR-processed copies are not matched. A Zotero 10 compatibility fork of heimi98/zotero-deduplicator.

What you'll need

Detected automatically

We haven't detected any setup requirements. That isn't the same as none: check the developer's README.

Where your data goes

We found: no web requests found.

Other plugins that do this

Matched on what they do

For the same job, work with Zotero 10 and graded A or better. Closest match first.

  • A+
    Zoplicate

    Catches duplicates the moment you import and asks whether to keep the new copy, the old one or both, then merges without losing attachments or notes.

    Matches “find duplicate items” · 1.02M downloads · Active · Zotero 9–10
Compare all 2 side by side
How we pick these

By how closely what they do matches this plugin, using descriptions and the phrases people search with. Copies and forks of this plugin are listed under Forks and copies instead. No plugin pays to appear here.

Forks and copies

1 other plugin uses the same ID as this one. Every Zotero plugin carries an ID, a name tag Zotero uses to tell plugins apart. These 2 plugins carry the same one, because people copied PDF Deduplicator to make their own versions and kept its ID.Show what this means
  • You can only have one. Zotero sees them as the same plugin.
  • Installing another replaces it. If you install one of the others, it takes this one's place.
  • Check what you install. Several share this plugin's name, so make sure the file comes from the one you meant.
PDF Deduplicator · this pluginCCsouljump/zotero-pdf-deduplicatorARecommended912 Oct 2026
PDF DeduplicatorThe most used · heimi98/zotero-deduplicatorARecommended5651 Nov 2026
See all 2 and how they differ →

No forks listed.

The developer's response

The developer hasn't responded. Developers can reply here, and their reply sits next to our findings.I'm the developer

Ratings and reviews

What people who use it say. This is separate from the grade, which is what the code does, and never changes it.

No ratings yet.

Write a review
Your rating of PDF Deduplicator v1.3.0

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Install PDF Deduplicator
ARecommended
  1. 1Download the plugin fileDownload v1.3.0.xpi · 0.01 MB
  2. 2In Zotero, open Tools › Plugins
  3. 3Click the gear, choose Install Plugin From File… and pick the file
Step-by-step guide with pictures