Privacy Policy

Last updated 3 October 2026

This policy explains what Dual Subtitles does with data. Tanglement is the trading name of Marc Bittner, a sole proprietor, based in California, United States. Contact: support@tanglement.ai. In this policy “we” means Tanglement.

Summary

Dual Subtitles reads the subtitle files your video player loads and shows them on screen. When a line needs translating, its text (only the text) is sent to the translation service you selected: MyMemory by default, or DeepL, Google Cloud, LibreTranslate or your own server if you configure one. A word you click is also sent to Wiktionary for definitions. Settings, saved words and a translation cache stay in your browser's extension storage. We run no server and collect no browsing history. Payments are handled by ExtensionPay and Stripe, which receive your email at checkout.

Data the product accesses

• The subtitle files your video player loads on the supported video sites (YouTube, Netflix, Prime Video, Disney+, Max, Crunchyroll, TED, Wikimedia Commons)
• Subtitle files you open yourself in the built-in local player

Data stored

WhatWhereHow longSettings (including any translation provider key, server URL or email you enter), saved words with their sentences, translation cache, daily usage countersyour browser's local extension storage on your deviceuntil you delete them or uninstall the extension

Data sent off your device or platform

WhatSent toWhyText of subtitle lines that need translating (only the text)the translation service you selected: MyMemory (default), DeepL, Google Cloud Translation, LibreTranslate or your own OpenAI-compatible / local LLM serverto translate the second subtitle lineThe optional email you enter for MyMemoryMyMemoryMyMemory gives a higher free daily limit when an email is suppliedYour API key, if you configure DeepL, Google Cloud or LibreTranslatethat providerto authenticate your own account with itA word you clickWiktionary (en.wiktionary.org)dictionary definitionsYour email at checkoutExtensionPay and Stripepayment and licence check

Third parties

• MyMemory (Translated) — default translation provider
• DeepL — optional translation provider with your own key
• Google Cloud Translation — optional translation provider with your own key
• LibreTranslate / your own LLM server — optional translation provider you host or choose
• Wiktionary — word definitions
• ExtensionPay — payments and licence check (privacy policy)
• Stripe — card payment processing for ExtensionPay (privacy policy)

Permissions and why they are needed

Permission / scopeWhystoragesettings, saved words, translation cacheHost access: api.mymemory.translated.net, translation.googleapis.com, api-free.deepl.com, api.deepl.comtranslation APIsHost access: en.wiktionary.orgword definitionsHost access: .nflxvideo.netfetching Netflix's second-language subtitle file the player listsHost access: extensionpay.combillingOptional host access (https:///*, localhost, 127.0.0.1)requested only when you add your own LibreTranslate or LLM server URLContent scripts on the supported video sitesread the subtitles the player loads and draw the second line

Analytics and tracking

None

No remote code.

Subtitle text sent to the translation provider is not sold and not used for anything else.

On streaming services, subtitles are displayed only and never saved as files; downloads are limited to TED, Wikimedia Commons and your own files.

On Firefox the add-on declares the websiteContent data-collection category, because subtitle text goes to the translation provider.

Dual Subtitles is not affiliated with Netflix, YouTube, Amazon, Disney, Warner Bros. Discovery, Crunchyroll or TED.

What we do not do

• We do not sell personal data.
• We do not use your data for advertising.
• We do not share your data except as described on this page.

When you contact support

If you email support@tanglement.ai, we receive your email address and whatever you put in the message. We use it only to answer you and keep it only as long as needed for that and for our records; ask and we will delete it.

Your choices and rights

You can stop all processing by uninstalling or disconnecting the product. You can ask us what data we hold about you, ask for a copy, or ask us to correct or delete it, by writing to support@tanglement.ai. Depending on where you live (for example the EU/UK under the GDPR, or California under the CCPA) you may have further rights; we honour them on request.

Children

The product is not directed to children under 13 (or the minimum age in your country), and we do not knowingly collect their data.

Changes

If this policy changes we will update this page and the date above. Material changes will also be noted in the product’s release notes.

Contact

Tanglement is the trading name of Marc Bittner, a sole proprietor, based in California, United States. Contact: support@tanglement.ai.