Get the overlay link first: Show captions on a screen or in your video mixer explains where it is and which colours to pick.
- In the Sources panel click +, choose Browser, name it Captions and click OK.
- Paste the overlay link into URL. Set Width to 1920 and Height to 1080, or to the size of your canvas. Leave the Custom CSS box as OBS fills it in.
- Untick Shutdown source when not visible and Refresh browser when scene becomes active. The source then keeps its caption connection while you switch scenes instead of reconnecting every time.
- Drag the source to the top of the Sources list in every scene that needs captions. If you use it in many scenes, put it in its own scene and add that scene as a source.
- Sound check: add
&preview=1to the end of the URL, right-click the source and choose Interact to see the status box. Remove it again once you see Receiving captions.
- Keep Background on Transparent on the Overlay link card. A Browser source is transparent by itself, so a coloured background would show as a rectangle. Transparent makes the page see-through, but the box behind the words stays. To show just the letters, set Text background to 0 under Settings → Screens, usually with a Text outline so they stay readable.
- One Browser source per language. Two overlays with different languages can run at the same time from the same card.
- After SynaiConnect is updated, an OBS source that has been open for days may still show the old page. Right-click it and choose Refresh.