Vocnu for online courses and lectures
The Vocnu extension for Chrome, Brave and Edge reads a lesson in your language over the teacher's lowered voice, with subtitles, while the course plays on its own site. We tried it on a Udemy lesson on 9 November 2026, and on TED, Vimeo and a video in a blog post the same week. For lessons we suggest Standard quality: an hour costs €3.96 to €6.00, and a new account's free credits cover 40 minutes of it.
For Chrome 120 or newer, Brave and Edge on a computer.
What happened on a Udemy lesson
On 9 November 2026 we opened the free preview of The Complete Python Bootcamp From Zero to Hero in Python on Udemy, an English lesson of almost four minutes on numbers in Python, and switched Vocnu on with Lithuanian as the language.
- The lesson had no captions Vocnu could use, so it translated what the teacher said.
- When we switched it on, the lesson paused with "Vocnu is preparing the voice-over…" while Vocnu listened ahead, then went back to the start.
- The first Lithuanian line came about a minute after we switched it on. From then on the teacher's voice played lowered under the Lithuanian one, with Lithuanian subtitles over the video.
- We sped the lesson up to 1.5x and the voice kept up.
- Udemy itself offered Lithuanian subtitles marked [Auto] on this course, but no Lithuanian audio.
Course and lecture sites we tried
| Where the video played | Tested | What Vocnu translated from | First line in your language |
|---|---|---|---|
| Udemy, a free course preview | 9 November 2026 | What the teacher said: the lesson had no captions it could use | About a minute after switching on |
| TED, a talk on ted.com | 6 November 2026 | The talk's own English subtitles | 39 seconds |
| Vimeo, a short film | 6 November 2026 | Vimeo's English subtitle track | 17 to 37 seconds |
| A YouTube video in a post on the Chrome for Developers blog | 8 November 2026 | The uploader's English captions | 39 seconds |
The Chrome blog video is a programming talk: its Lithuanian subtitles kept abbreviations such as CSS as written instead of spelling them out. We have not tried Coursera, Skillshare, LinkedIn Learning or a school's own course platform yet. A course site that plays its lessons in an embedded YouTube or Vimeo player uses the same players as the rows above, but only the sites in this table were tested.
Which quality to pick for lessons
You choose a voice-over quality for each video, and the extension remembers your last choice. A course is long and you mostly want to follow what is said, so Standard is the one we suggest for it.
| Quality | An hour of lessons | A 10-hour course | Pick it when |
|---|---|---|---|
| Premium | €7.92 to €12.00 | €79 to €120 | Every term has to be right, as in law, finance or programming, or you will listen to the voice for hours |
| Standard | €3.96 to €6.00 | €40 to €60 | Most lessons and lectures: clear voices and a good translation for half of Premium's credits |
| Economy | €1.98 to €3.00 | €20 to €30 | The price matters most and a plain synthetic voice is fine, on recorded lessons |
The prices run from the largest credit pack to the smallest. Watching the same minutes again within 30 days, in the same language, voice and mode, is free, so going back over a hard part costs nothing. A lesson already in your language is never voiced or charged.
Set it up for a course
- Add Vocnu to Chrome, Brave or Edge from the Chrome Web Store.
- In the Vocnu app the extension opens, sign in or create a free account, and press Connect the extension.
- Open the lesson on the course site and click the Vocnu button in the browser's toolbar.
- Turn on "Vocnu on this tab", pick your language under "Translate into" and Standard under "Voice-over quality".
- Play the lesson. It may pause for a moment at the start while the first lines are prepared.
Vocnu is switched on one tab at a time. In a new tab, or after the browser restarts, click the button again or press Alt+Shift+V. Your language, voice and quality stay as you left them.
Setting it up for a parent or a student
If the person taking the course does not read English well, you can set it up on their computer and connect the extension to your own account, so the credits come from yours. Show them the Vocnu button and Alt+Shift+V, since each new tab needs it once. These are the messages they may see, and what to do:
- "Vocnu is preparing the voice-over…": wait; the lesson goes on once the first lines are ready.
- "To voice this video, let Vocnu hear it: click the Vocnu button in the toolbar.": click the button once.
- "This video is already in the language you chose.": there is nothing to translate, and nothing is charged.
- "Out of credits": add credits to the account, and the voice-over goes on by itself.
When the course's own subtitles are enough
If the course has subtitles in your language and you are happy to read, use them: they cost nothing extra. Vocnu is worth it when you would rather listen, for example when the teacher types code or works on screen while talking and your eyes are busy, or in a lecture you follow while taking notes, or when the course has no subtitles in your language at all.
When Vocnu is not the right pick
- The course already has audio in your language, or its subtitles are all you need.
- You study on a phone, a tablet or a TV, or in a course site's app. Vocnu works in Chrome, Brave and Edge on a computer.
- You want lessons to watch offline. The extension downloads nothing; it voices the lesson while it plays.
- You need the exact words of a live class. A live stream is voiced a few seconds behind the picture, and a line that would come too late shows as a subtitle only.
- You want the teacher's own voice, or a different voice for each speaker in a panel. One voice reads every line.
- You made the course and want to sell it in other languages. That is a different job: see Vocnu for course creators.