IDN-Warner

Name: IDN-Warner
Rating: 4 (3 reviews)
Author: Mirclus

By: Mirclus

Warns if a domain or subdomain is an internationalized domain name to prevent fishing attacks.

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Features & Capabilities

IDN-Warner is a Chrome extension designed to enhance your online security by detecting and warning you about Internationalized Domain Names (IDNs) that may resemble trusted domains. Phishing attackers often exploit visually similar Unicode characters to trick users into visiting malicious sites. This extension places a clear icon in your browser's address bar whenever a domain or subdomain is an IDN, regardless of how the browser displays the URL.

By alerting you to these potentially deceptive domains, IDN-Warner helps prevent phishing attacks and ensures safer browsing. It works independently from the browser's native URL display, providing an additional layer of protection against homograph spoofing threats.

User Growth & Download Statistics

Add-on Privacy & Security Developer Tools

By:

Mirclus

Daily users:

49 1

Rating:

4.00

(3)

Version:

1.1resigned1 Last updated: 2024-04-25

Version code:

5729848

Creation date:

2018-01-05

Risk:

Permissions:

<all_urls>
tabs
webNavigation

Size:

15.39KB

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-06-20

Compare stats and ranking:

Ranking

# 15,716 ▲ 129

Other rankings

#121 in earn keyword 32 ▲ 3#178 in domain keyword 26 ▲ 1#229 in prevent keyword 36 ▼ 2

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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:

Mirclus

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/idn-warner/

User Reviews

by 天灭*****, 2025-04-14

by 远离*****, 2025-03-09

Yeah, it shows a little thing indicating you went to a punycode website. That doesn't solve anything, though, because that means you've already GONE to said website and so potentially exposed yourself. It should instead block IDN URLs from even loading and give a warning, just like warnings for redirects and such. So yeah, this add-on works as intended/described, it's just totally useless. Really don't get why no one has done this seemingly simple thing, yet. (Nor why Mozilla refuses to actually protect their userbase by doing it themselves).

by Fi*****, 2020-12-16

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Is IDN-Warner 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.

IDN-Warner requires some sensitive permissions that could impact your browser and data security. 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.

IDN-Warner has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details

High This extension has low user count. Unpopular extensions may not be stable or safe.
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