Vocnu for lectures and talks
Recorded lectures, conference talks and webinars often run two or three hours, and YouTube's automatic dubbing skips every video over 120 minutes. The Vocnu extension for Chrome, Brave and Edge reads such a recording in your language over the speaker's lowered voice while it plays on the lecture's own site, with captions or without. On 10 November 2026 a German talk on media.ccc.de, two hours in, gave us its first Lithuanian line 56 seconds after we switched Vocnu on. A two-hour lecture costs €7.92 to €12 in Standard quality. Vocnu is for recordings and streams you watch: a meeting you speak in needs an interpreter.
For Chrome 120 or newer, Brave and Edge on a computer.
Long talks we watched with Vocnu
Each test ran in Chrome with the Vocnu extension, timed from switching it on to the first line in the new language. We started the two long ones past their two-hour mark, where YouTube would no longer dub.
| Recording | Tested | Vocnu translated from | First line |
|---|---|---|---|
| A German conference talk of 2 hours 2 minutes on media.ccc.de, into Lithuanian from 2:00:25 | 10 November 2026 | What it heard: the talk has no captions | 56 seconds |
| A NASA briefing of 2 hours 5 minutes on YouTube, into Spanish from 2:01:00 | 10 November 2026 | NASA's own English captions | 22 seconds |
| A TED talk on ted.com, into Lithuanian | 6 November 2026 | The talk's own English subtitles | 39 seconds |
| Vimeo's player, on a short film rather than a talk, into Lithuanian | 6 November 2026 | Vimeo's English subtitle track | 17 to 37 seconds |
On the German talk, the speakers dropped to about a fifth of their volume under the Lithuanian voice, and after we reloaded the page the voice-over was back in 39 seconds. On the NASA briefing, the line we noted was "Habrá muchísimas pruebas antes de que nos encontremos con estos vehículos en orbita", right but for the missing accent of "órbita". The briefing is NASA's and in the public domain; NASA does not endorse Vocnu.
Why YouTube leaves long lectures undubbed
YouTube's help page on automatic dubbing, as we read it on 10 November 2026, gives "The video exceeds 120 minutes" as the first reason a video gets no dub. NASA's channel showed it the same day: "Moon Base: November 2026 Update", 1 hour 36 minutes long, offered English and 20 automatic dubs in its audio menu, while the 2 hour 5 minute briefing above offered none. A Spanish speaker had translated subtitles at most.
Under 120 minutes, YouTube dubs English videos into 20 languages and most other languages only into English. If yours is left out, see languages YouTube does not dub.
Watch it in the tab, or upload the recording
| What matters | The extension, as it plays | An upload in the Vocnu app |
|---|---|---|
| Where | On the lecture's own page, in Chrome, Brave or Edge on a computer | A recording you have as a file and may translate |
| Length | As long as it plays; our tests ran past the two-hour mark | Up to 5 hours and 10 GB a file |
| What you keep | Nothing: you hear the voice and see subtitles while you watch | A video with the voice-over and the original as two audio tracks, subtitles and a transcript, kept for 30 days |
| What you pay for | The minutes Vocnu voices, so a part you skip costs nothing | The whole file, quoted before the job starts |
| Fits | A talk you watch once, on any site | A webinar your team will watch again, or a lecture to take on a flight |
We uploaded the same German talk, a 276 MB MP4 of 2 hours 2 minutes, for Lithuanian in Standard quality on 10 November 2026. It cost 123 credits, €8.12 to €12, and the finished video was ready in under half an hour. It came back with the Lithuanian voice-over as its main audio, the German original as a second track and subtitles in both languages, with the Lithuanian subtitles as SRT, VTT and ASS files and a German transcript. The recording's English and French interpreter tracks were not kept, and one Lithuanian voice read all five speakers.
Two of its lines: "Herzlich willkommen zum Jahresrückblick des CCC 2024." became "Sveiki atvykę į 2024 metų CCC apžvalgą.", and "Wir sind ein Verein, wie es sich gehört, für gute Deutsche." became "Kaip ir dera geriems vokiečiams, esame asociacija." The talk is "Der CCC-Jahresrückblick" from 38C3 by erdgeist, kantorkel, khaleesi, Linus Neumann and Constanze Kurz, published on media.ccc.de under CC BY 4.0; the Lithuanian voice-over and subtitles were added by Vocnu.
What a lecture costs
With the extension you pay for the minutes Vocnu voices, in the quality you pick:
| Recording | Standard | Premium | Economy |
|---|---|---|---|
| An hour | €3.96 to €6.00 | €7.92 to €12 | €1.98 to €3.00 |
| A 45-minute talk | €2.97 to €4.50 | €5.94 to €9.00 | €1.52 to €2.30 |
| A two-hour lecture | €7.92 to €12 | €16 to €24 | €3.96 to €6.00 |
| A three-hour webinar recording | €12 to €18 | €24 to €36 | €5.94 to €9.00 |
The prices run from the largest credit pack to the smallest. Standard suits most talks. Premium is for a talk dense with terms you need exactly right, and Economy, a plain synthetic voice, for one you only want the gist of. A new account's free credits cover 40 minutes of Standard, so you can try the first part of a talk before you buy. Going back over a part within 30 days, in the same language, voice and mode, costs nothing.
Watch a lecture in your language
- Add Vocnu to Chrome, Brave or Edge from the Chrome Web Store, sign in or create a free account in the app it opens, and press Connect the extension.
- Open the recording on its own page: a conference's video site, YouTube, Vimeo or TED.
- Click the Vocnu button in the browser's toolbar, turn on "Vocnu on this tab" and pick your language and Standard quality.
- Play the talk, or jump straight to the part you came for. Without captions, Vocnu listens a little ahead, so the talk pauses at the start and after a jump past what it has heard; on the German talk that first wait was under a minute.
- Leave the tab playing. Vocnu works one tab at a time: in a new tab, click the button again or press Alt+Shift+V.
Not an interpreter for meetings
Vocnu voices video you watch. It does not interpret a Zoom, Teams or Meet call you take part in, or carry a speaker's words to an audience in the room, and we have not tested it on a meeting app. For a meeting, book an interpreter or check whether your meeting tool translates captions.
A webinar or conference streamed live on YouTube is a different case: Vocnu voices it a few seconds behind the picture, as on the news streams in Vocnu for news and live streams.
When Vocnu is not the right pick
- The recording already has an audio track or good subtitles in your language. On YouTube, look in the audio track menu first: a dub there is free.
- The slides carry the lecture. Vocnu translates what is said; the text on the slides stays as it is.
- A panel should sound like several people. One voice reads every speaker, as it read all five on the German talk.
- You watch on a phone, a tablet or a TV. The extension runs in Chrome, Brave and Edge on a computer; elsewhere, upload a recording you may translate and play the file.
- You need a quotation exact enough to cite. Check the speaker's own words before you quote them.
- You are taking a course of many short lessons. Vocnu for online courses covers that, with a Udemy test.