OBS Browser Source dimensions: fit an overlay with no gaps
If an OBS Browser Source overlay shows blank edges, crops the wrong area, or does not fit the scene, the fix is usually to match the source dimensions to the overlay layout and then position or crop the source intentionally.
Updated 2026-08-01. Built from creator setup questions and Search Console/Bing query signals.
Short version
For full-screen overlays, set the Browser Source width and height to your canvas size, such as 1920 × 1080 or 1080 × 1920. For StreamRio pet overlays, use a 4:5 source like 720 × 900 or 800 × 1000, then place the character near a corner or beside chat. Avoid stretching a pet overlay to full screen unless the overlay itself was designed for full-screen use.
Choose source dimensions based on overlay type
A chat widget, full-screen alert, and animated pet overlay should not all use the same dimensions. Start by deciding whether the overlay is full-scene, panel-style, or character-style.
- Full-scene overlay: 1920 × 1080, 1280 × 720, or 1080 × 1920.
- Vertical stream overlay: 1080 × 1920 or a smaller vertical panel.
- Character/pet overlay: 720 × 900, 800 × 1000, or another 4:5 rectangle.
- Narrow widget: match the widget’s intended width instead of stretching it.
Why blank gaps happen
Blank gaps usually appear because the web page inside the Browser Source has a different aspect ratio than the OBS source box. If the web layout is 4:5 but the OBS source is square or widescreen, empty space or cropping can appear.
- Square source used for a tall character overlay.
- Full-screen source used for a small pet widget.
- CSS safe area or padding inside the overlay page.
- Wrong transform after resizing or cropping in OBS.
Recommended StreamRio pet overlay setup
For a StreamRio pet, use a 4:5 Browser Source and keep it smaller than your camera or gameplay. This gives the character enough vertical room for idle and reaction animations without forcing it into a full-screen frame.
- Source type: Browser Source.
- Size: 720 × 900 or 800 × 1000.
- Background: transparent.
- Placement: lower corner, beside chat, or beside your camera frame.