---
title: "Library Check for Zotero – Prevent Duplicates – Chrome extension stats, history and permissions"
description: "1,000 users, rated 5.00 by 1 person. Version 1.7.0, updated 2026-09-16. Requests 5 permissions."
url: "https://extensiontracker.com/extension/njakhbdjddaflodiogjmbledldjjbbai"
---

# Library Check for Zotero – Prevent Duplicates

Live in the Chrome Web Store.

- Users: 1,000
- Rating: 5.00 from 1 rating
- Last checked: 2026-09-27 06:17 UTC
- Users gained in 7 days: – (needs a week of history)
- Users gained in 30 days: – (needs a month of history)
- Rank by users: #17,733 of 264,703 live extensions
- Rank in Tools: #4,498 of 103,498

## The listing

What the Chrome Web Store shows, as of the last check.

Summary from the listing:

> Check instantly whether the paper you're viewing is already saved in Zotero. A simple tool to prevent duplicate saves.

- Extension ID: `njakhbdjddaflodiogjmbledldjjbbai`
- Developer: [Yukihiro Marui](https://extensiontracker.com/developer/uee8e965af2d2eace893a8e423193ea8b)
- Category: [Productivity › Tools](https://extensiontracker.com/category/productivity/tools)
- First published: 2026-02-25
- Last updated: 2026-09-16
- Version: `1.7.0`
- Size: 194 KiB
- Minimum Chrome: 88
- Languages (7): English, español, français, português (Brasil), हिन्दी, 中文（中国）, 日本語
- Privacy policy: `https://gist.githubusercontent.com/y-marui/2c824444502e777a0dbdb353ec3df725/raw/Privacy%2520Policy%2520%25E2%2580%2593%2520Zotero%2520Library%2520Checker`
- Chrome Web Store: <https://chromewebstore.google.com/detail/library-check-for-zotero/njakhbdjddaflodiogjmbledldjjbbai>
- View the code or download the CRX, in CRX Viewer: <https://robwu.nl/crxviewer/?crx=https%3A%2F%2Fchromewebstore.google.com%2Fdetail%2Fnjakhbdjddaflodiogjmbledldjjbbai>

## Users over time

One row per check, newest first, as shown on the Chrome Web Store.

| Checked | Users | Rating | Ratings |
| --- | ---: | ---: | ---: |
| 2026-09-27 | 1,000 | 5.00 | 1 |

## What changed

Every change found on a check, newest first.

No changes found since tracking began on 2026-09-27.

## What it can access

From the extension's manifest, in plain language.

**Every website:** it can read and change your data on all the sites you visit.

### Sites

- `http://127.0.0.1:23119/*`: 127.0.0.1:23119
- `http://localhost:23119/*`: localhost:23119

### Sites where it runs scripts

- `<all_urls>`: Every website

### Browser features

- `activeTab`: The tab you're on, only after you click the extension
- `storage`: Save settings and data in your browser
- `tabs`: Read the addresses and titles of your tabs

## More from this developer

Other extensions from the same publisher account.

| Extension | Users | Rating | Ratings | Category |
| --- | ---: | ---: | ---: | --- |
| [Focus Scope - Smart Website Blocker](https://extensiontracker.com/extension/dnpccglkhnnlogdolajjhehicbegnlcg) | 12 | – | – | Tools |

All 2 extensions by [Yukihiro Marui](https://extensiontracker.com/developer/uee8e965af2d2eace893a8e423193ea8b).

## About this data

Collected from the extension's public Chrome Web Store listing. It's checked every week, because it has 1,000 or more users, and again whenever a new version appears. Last checked 2026-09-27 06:17 UTC; next check around 2026-10-03.

How the data is collected: <https://extensiontracker.com/methodology>.

## Cite this page

Extension Tracker. “Library Check for Zotero – Prevent Duplicates” (njakhbdjddaflodiogjmbledldjjbbai). Chrome Web Store data, last checked 2026-09-27. https://extensiontracker.com/extension/njakhbdjddaflodiogjmbledldjjbbai. Accessed 2026-09-28.

```bibtex
@misc{extensiontracker_njakhbdjddaflodiogjmbledldjjbbai,
  title   = {Library Check for Zotero – Prevent Duplicates (njakhbdjddaflodiogjmbledldjjbbai)},
  author  = {{Extension Tracker}},
  year    = {2026},
  note    = {Chrome Web Store data, last checked 2026-09-27},
  url     = {https://extensiontracker.com/extension/njakhbdjddaflodiogjmbledldjjbbai},
  urldate = {2026-09-28}
}
```

---

From Extension Tracker, a public record of the Chrome Web Store: <https://extensiontracker.com/extension/njakhbdjddaflodiogjmbledldjjbbai>. It isn't affiliated with Google. The data is free to reuse under CC BY 4.0 (<https://creativecommons.org/licenses/by/4.0/>), crediting Extension Tracker. Extension, developer and list pages come as Markdown too: add `format=md` to the address, as in `https://extensiontracker.com/extension/{id}?format=md`.