Unpaywall

Name: Unpaywall
Rating: 4.332 (250 reviews)
Author: Impactstory team

By: Impactstory team

Get free text of research papers as you browse, using Unpaywall's index of ten million legal, open-access articles.

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Features & Capabilities

Unpaywall is a free, open-source Chrome extension that unlocks access to scholarly articles behind paywalls. When you encounter a paywalled research paper, Unpaywall checks its vast database of 16 million legal, open-access articles and displays a green tab if a free version is available. Simply click the tab to read the research paper legally and without cost. Developed by Our Research, a nonprofit focused on making academic work more accessible, Unpaywall enhances your research experience by seamlessly integrating open-access content into your browsing. This tool promotes transparency, knowledge sharing, and democratizes academic information worldwide.

User Growth & Download Statistics

Add-on Education Open Source

By:

Daily users:

Rating:

Version:

3.98 Last updated: 2021-07-28

Version code:

5272498

Creation date:

2017-03-04

Risk:

Permissions:

*://*.oadoi.org/*
storage

Content scripts matches:

<all_urls>

Size:

675.66KB

Email:

su*****@unpaywall.org

URLs:

Website ,Privacy policy

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-06-18

Compare stats and ranking:

Ranking

# 266 ▼ 4

Other rankings

#19 in Feeds, News & Blogging

#26 in Search Tools ▼ 1

#34 in Social & Communication

#3 in legal keyword 8

#27 in article keyword 45 ▲ 1

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Other platforms

Unpaywall (v3.99)

900,000 3.98

(279)

For Developers

Monetize with App Pass Boost with Extension Booster

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

Impactstory team

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/unpaywall/

Email:

su*****@unpaywall.org

Website:

https://unpaywall.org/products/extension

User Reviews

User reviews are mixed: many praise Unpaywall for locating open-access scholarly papers and supporting free education, while others report it not working reliably, confusion about the tool’s purpose, branding issues, and potential privacy concerns.

Pros

Helps locate open access versions of scholarly articles (green unlocked icon) when available.
Saves time by reducing manual searching for open copies of papers.
Regarded by users as a useful add-on that does what it’s supposed to do.
Supports the goal of free education by making scholarly papers more freely accessible.

Cons

Some users experience not working or inconsistent functionality (icon may not respond or opens a new tab instead).
Confusion about what Unpaywall does and its scope (not for news, only scholarly articles).
Branding/name confusion leading to potential misunderstandings.
Privacy concerns or perception that the extension might collect data.
Occasional technical quality concerns (e.g., code differences in jQuery).

Recent reviews

Saves lots of time searching ResearchGate and arXiv. Could work better with certain Elsevier journals such as Nuclear Instruments and Methods.

by Qu*****, 2026-06-04

by Ni*****, 2026-05-28

by Fi*****, 2026-04-05

View all user reviews ›

Is Unpaywall Safe?

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Unpaywall requires a few sensitive permissions. Exercise caution before installing.

Risk impact analysis details

Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
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Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Unpaywall has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details

Low This extension was updated more than 6 months ago. Older versions are more likely to be stable and safe.
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