Is LangKey · Dual Subtitles & Language Learning (YouTube, Netflix) safe to install?

What data it declares

The developer declares that it collects these kinds of data:

• Financial and payment information such as transactions, card numbers or credit history
• Personal communications such as emails, texts or chat messages
• Location such as region, IP address or GPS coordinates

The developer also certifies that your data is not sold to third parties outside approved uses, not used for purposes unrelated to the extension's core function, and not used to decide creditworthiness or lending.

The listing links to a privacy policy.

This is the developer's own declaration in the Chrome Web Store. We cannot check it against what the extension does.

What Chrome asks you to allow

When you add it, Chrome asks you to allow it to:

• Read and change all your data on all websites
• Block content on any page
• Read your browsing history

Derived from the manifest by Chrome's documented rules; the dialog's exact wording depends on your Chrome version and language. Chrome asks again if an update requests more.

What it can reach

Every site you visit. This extension can read and change the content of any page you open. What access to every site means

Reaches your browsing data or every site

• See the address and title of every tab you have open tabs
• Watch the network requests your browser makes webRequest

Worth knowing

• Block or redirect requests by rules it declares in advance declarativeNetRequest
• Run its own code on the pages it can access scripting

Routine for an extension

• Act on the current tab, but only after you click it activeTab
• Add items to the right-click menu contextMenus
• Run work in a hidden page offscreen
• Open a panel beside the page sidePanel
• Store data in your browser storage

Pages it runs its code on

It runs its own code on every page you open: the manifest declares a content script for all sites.

• *://*.youtube.com/* youtube.com and all its subdomains
• *://*.bilibili.com/video/* bilibili.com and all its subdomains
• *://*.ted.com/* ted.com and all its subdomains

A content script is code the extension injects into pages matching these patterns. On those pages it can read and change what you see, whether or not a host permission is listed above.

How usual this is for its category

In Productivity · Education, 17% of extensions ask for access to every site. This one: Access to every site.

The typical extension there declares 3 browser permissions; this one declares 9 browser permissions.

• See the address and title of every tab you have open (tabs): 21% of extensions in this category ask for it.
• Watch the network requests your browser makes (webRequest): 2% of extensions in this category ask for it.

Counted over the live extensions of the same category after our latest full pass of the store. A share is context, not a verdict: what is normal depends on what the extension is for.

Who uses it and how it is kept up

251 users

• Last updated in the store 11 days ago, on 2026-10-22.
• We have seen 2 new versions in the last 90 days.

What the store shows

• Established publisher The store's badge for publishers with a good record and no history of violations.

Has it asked for more over time?

This is the question a permission list on its own cannot answer. An extension that shipped narrow and widened later is a different proposition from one that always asked for the same thing.

1. 2026-10-22Asked for more permissions (33, was 31) (changed: site access, pages it runs its code on)

Versions we have seen

1. 2026-10-22Version 2.4.3 · Asked for more permissions (33, was 31) (changed: site access, pages it runs its code on)
2. 2026-09-06Version 2.4.2

Who publishes it

The store lists no publisher name. This listing has been in the store since 2025-08-04 and was last updated on 2026-10-22.

Similar extensions that ask for less

Listings close to this one in what they say they do, which declare less reach. Less reach is not a verdict on either: compare what each needs for the job.

1. LangHub — Learn Languages from Subtitles Runs its code on every site · 4 permissions, 6 site patterns 9 users
2. ClipToClass: AI Dual Subtitles & Language Lessons Access to specific sites only · 6 permissions, 10 site patterns 133 users ★ 5.0
3. Telidioma: Interactive YouTube Subtitles Access to every site · 3 permissions, 1 site pattern 1k users ★ 5.0

How to check or remove it in Chrome

1. Type chrome://extensions in the address bar and find the extension in the list.
2. Open its details. The site access setting shows where it can run; set it to run only on click and it reaches a page only after you press its icon.
3. To uninstall it, choose Remove on the same page.

Questions people ask

What can LangKey · Dual Subtitles & Language Learning (YouTube, Netflix) access?

Every site you visit. This extension can read and change the content of any page you open. It declares 9 browser permissions.

What data does LangKey · Dual Subtitles & Language Learning (YouTube, Netflix) collect?

The developer declares that it collects these kinds of data: Financial and payment information, Personal communications, Location. This is the developer's own declaration in the Chrome Web Store. We cannot check it against what the extension does.

Has LangKey · Dual Subtitles & Language Learning (YouTube, Netflix) asked for more permissions over time?

Its permissions changed once while we watched, on 2026-10-22.

Does LangKey · Dual Subtitles & Language Learning (YouTube, Netflix) publish a privacy policy?

Yes, the store listing links to a privacy policy.