About InterSub
Who we are and whom we help
We build InterSub for people who want to learn a language, most often English, but cannot give it hours of intensive study. They still want their understanding and vocabulary to grow, or at least to keep the level they already have. Some call them lazy learners. We call them busy people with interests of their own.
Learning should fit into habits you already have. You watch what interests you, whether a series, a film, a lecture for work or an article on a topic you follow, in the language you learn. InterSub makes it comfortable, so the language never spoils the story or slows you down. And there is more to watch in English than in most other languages, so English gives you the widest choice.
Our idea: learning around what interests you
- You choose the content. The shows, videos and sites you would open anyway, instead of an app's ready-made topics or a course that gets boring.
- Minimum effort. InterSub gives you what you need at the moment you need it and does the rest automatically: every word you look up is saved with the line it came from, without extra clicks.
- Your own pace. Watching with dual subtitles is enough to keep moving. When you want more, the words you collected are already waiting.
- A learning loop built on your words. The words from what you watched become the material you practice. The first place to practise them is our Telegram bot; you can also sync them with Anki.
What InterSub does
- Dual subtitles. The line in the language you learn and the line in your own language appear one above the other. The how-to page lists the supported platforms.
- Pop-up dictionary. Hover over a word in the subtitles and the video pauses. A pop-up shows a definition and a translation that fits the scene.
- AI subtitle translation. If a video has no subtitles in your language, InterSub can translate the original line with AI and show it as the second line. It is included in paid plans.
- Translator on any website. Select a word or phrase on any page to see its translation in context.
- AI Language Buddy. A chat where you can ask what a word means in this scene, how the grammar works or what a cultural reference is about.
- Wordbook. Every word you look up is saved with the line it came from. You can open the list in your web account.
- Word practice. Sync saved words with Anki or train them in our Telegram bot.
- Remote Control. Scan a QR code on the video to pause it and look up words from your phone while you watch on a big screen.
Each tool is described in more detail on the features page.
How our approach differs
- Dual subtitles are free. Paid plans add more word lookups and AI subtitle translation; see plans and prices.
- You can use your words outside InterSub: sync them with Anki, practice them in our Telegram bot or export them to Excel.
- Every new account gets a 14-day free trial of Premium, and payments, including renewals, can be refunded within 14 days through support.
- We publish every version and what changed in it on the feature updates page.
Who InterSub is for
InterSub is for people who learn at a relaxed, steady pace: alongside work and life, from the content they enjoy, sometimes just to keep their English in shape. It suits any level, beginners included: the second subtitle line lets you follow the story while you hear the language you learn. People use it for series and films, for courses on Coursera, Udemy and LinkedIn Learning, and to learn Japanese from anime on Crunchyroll and Bilibili.tv. It supports more than 30 languages, including right-to-left ones such as Arabic and Hebrew.
InterSub may not be enough for advanced learners who study intensively and want every tool for it. We are fine with that: we build for people who cannot, or do not want to, study that way.
Current limits:
- InterSub works in desktop browsers: Google Chrome, Microsoft Edge and Firefox. Other Chromium browsers, such as Brave and Arc, use the Chrome version.
- Safari and a mobile version are not available yet. On a phone you can use Remote Control and practice saved words, but you cannot watch videos with InterSub.
- InterSub works with the subtitles the video platform provides. It does not create captions from the audio.
Where InterSub is going
The Telegram bot is the first interface of this learning system. Other interfaces will follow, including practice right in the extension. The next step is an AI tutor for speaking practice, built around the same words and the topics you care about.
Who is responsible
InterSub was founded in 2022 by Kirill Rozhkovskiy and Dennis Crane. Kirill Rozhkovskiy leads the product and the company today.
The extension is developed and published by InterSub Inc., 220 East 23rd Street, Suite 400, New York, NY 10010. The company is listed as the developer of InterSub in the Chrome Web Store and Microsoft Edge Add-ons.
How we work with users
- Feedback. Tell us what works and what does not through the feedback form.
- Support. Write to support@intersub.cc.
- Community. Join our Discord server or follow us on Facebook.
- Updates. We release new versions for Chrome, Edge and Firefox at the same time and describe each one on the feature updates page.
- Help. Setup instructions for each platform are on the how-to page, and common questions are answered in the FAQ.
Key facts
| Product | InterSub, a browser extension with dual subtitles and a pop-up dictionary |
|---|---|
| Company | InterSub Inc. |
| Founded | 2022 |
| Founders | Kirill Rozhkovskiy, Dennis Crane |
| Address | 220 East 23rd Street, Suite 400, New York, NY 10010, USA |
| Website | intersub.cc |
| Browsers | Google Chrome, Microsoft Edge, Firefox (desktop). Safari and mobile: not yet available |
| Video and course platforms | YouTube, Netflix, Prime Video, HBO Max, Crunchyroll, Bilibili.tv, TED, Coursera, Udemy, LinkedIn Learning, Domestika, DW Learn German, Learn.cantrill.io, Shahid. Full list: /en/how_to |
| Languages | 30+, including right-to-left languages such as Arabic and Hebrew |
| Website languages | English, Russian, Ukrainian, Spanish, Portuguese |
| Users | 50,000+ |
| Plans | Free (dual subtitles, monthly word lookup limit), Pay-as-you-go, Premium; 14-day Premium trial for new accounts |
| Chrome Web Store rating | 4.6 out of 5 from 227 ratings (checked 18 October 2026) |
| Microsoft Edge Add-ons rating | 4.9 out of 5 from 98 ratings (checked 18 October 2026) |
| Current version | 4.51.1 in all three stores (checked 18 October 2026) |
| Contact | support@intersub.cc |