StreamTranslateOBS sends the video stream
Choose the intended YouTube destination in OBS and verify the broadcast title and privacy in Studio. For a private test, use a dedicated stream key so you do not accidentally send video to a public broadcast associated with your usual key.
Connect your caption audio separately
Use the StreamTranslate OBS audio filter on the intended audio source, or another supported audio input route. The plugin key must belong to the same environment and account as Control. A staging key paired with the production server will be rejected.
Check that the selected source actually contains the speech you want captioned. OBS’s audio meter proves audio exists in OBS; also check StreamTranslate’s live preview for received speech.
Connect native CC in Control
- Set the spoken language.
- Choose YouTube CC and the desired subtitle language.
- Match the caption language in Studio.
- Copy that broadcast’s POST captions URL into Control and enable captions.
- Confirm captions on that broadcast’s actual watch page.
Test a reconnect
During a private test, interrupt and restore the caption audio connection. Check that new speech returns, old text is not replayed as new speech, and the captions remain on the same broadcast. Never treat the plugin’s connected state alone as proof that YouTube received the text.
Keep a staging rehearsal isolated
Use a private broadcast and a staging Control page when rehearsing a staging build. Check the OBS filter’s server setting as well as its plugin key. A production filter connected to production does not provide audio to the staging room you are viewing. Confirm new spoken text appears in the intended Control page before troubleshooting YouTube. Keep your normal broadcast profile available so you can return to it after the private test without replacing the default stream destination.
Sources and setup limits
See YouTube’s official requirements for the underlying caption transport and latency modes. Actual behavior must also be checked on your own broadcast.
Common questions
Do I add a browser source for native CC?
Native CC uses the caption ingestion URL. A browser source is only required when you also want a subtitle overlay in the picture.
Why is the plugin receiving audio but CC is grey?
Audio receipt and YouTube caption delivery are separate stages. Verify Control has captions enabled, the selected destination is the same broadcast, and the player has received caption text.