Using suPlay Poll as an OBS overlay

If you don’t use PowerPoint, or you want a single workflow that works across every slideshow tool — LibreOffice Impress, OnlyOffice, Keynote, Google Slides, Canva, Prezi, or a PDF reader in full screen — OBS Studio can project a transparent suPlay Poll overlay on top of your deck. Same setup on Windows, macOS, and Linux.

What you’ll need

• OBS Studio 30 or newer — free download.
• A suPlay Poll event with at least one poll and its join code (the 3–4 letter code shown on the event page). The display URL is https://poll.suplay.nl/event/<CODE>/display — public by design, no login needed, which is why OBS can load it.
• A second display, or a single display with Windowed-Projector mode (explained below).

Fastest start — import the ready-made scene

1. Download the pre-built scene collection: suplaypoll-obs-scene.json.
2. In OBS: Scene Collection > Import, pick the file, click Import, then switch to the new suPlay Poll collection from the same menu.
3. Double-click the suPlay Poll Live Feed source. Replace REPLACE_WITH_YOUR_JOIN_CODEwith your event’s join code (the 3–4 letter code shown on the event page).
4. Click OK. The scene is ready.
5. Right-click the preview → Fullscreen Projector (Preview) on your external display. Start your slideshow in your favourite presentation tool behind it.

Manual setup (if you prefer)

Takes about two minutes. Works identically on every OS.

1. Open OBS. In Scenes, click + and name the scene suPlay Poll Overlay.
2. In Sources, click + → Browser. Name it suPlay Poll Live Feed.
3. Paste your live-feed URL into the URL field, e.g.
   https://poll.suplay.nl/event/YOUR_JOIN_CODE/display
4. Set Width 1920 and Height 1080 (or whatever your output resolution is).
5. Paste this into Custom CSS so the page background is transparent and the overlay sits cleanly on top of your slideshow:

   body, html { background: transparent !important; margin: 0; padding: 0; }
   .no-overlay { display: none !important; }

6. Leave Shutdown source when not visible checked (saves CPU). Click OK.

Putting it on top of your slideshow

OBS by default renders to its own preview. To overlay it on your actual deck you have three patterns — pick one:

A. Dual-display projector (recommended)

1. Start your slideshow on your external display as you normally would.
2. Right-click the OBS preview → Windowed Projector (Preview), drag it onto the external display, press F11 to go fullscreen. Position / resize as you like — the transparent background lets your slides show through.
3. The OBS projector window always floats above the slideshow because it’s a normal window, not a system overlay. On macOS, enable Window > Float on Top from the OBS menu if needed.

B. Virtual camera into Zoom / Teams / Webex

1. In OBS, click Start Virtual Camera (bottom-right dock).
2. In Zoom / Teams / Webex, pick OBS Virtual Camera as your camera, and share your slideshow window as usual. Your remote audience now sees the suPlay Poll overlay composited on your slides.
3. This is the only approach that works reliably for remote meetings — OS overlays don’t travel through screen sharing.

C. Record or stream

Use OBS’s normal Record / Stream buttons. The overlay is baked into the recording / RTMP stream. Handy for async workshops and YouTube / Twitch broadcasts.

Tips

• Audio:suPlay Poll doesn’t emit audio. Leave the Browser source’s audio monitoring off.
• Refresh on update: if you change poll visibility or results mid-event, OBS picks it up automatically via Socket.io. No refresh needed.
• Chroma key: not needed — the Custom CSS above already makes the background transparent.
• Resolution: match the Browser source resolution to your output canvas (Settings > Video > Base Resolution) to avoid blurry scaling.
• CPU: one Browser source costs roughly what one Chrome tab costs. On an Intel i5 from 2018 the overhead is under 5%.

Troubleshooting

• Blank / black overlay: the display URL only renders when the event is LIVE or CLOSED. If the event is still DRAFT, activate at least one poll and try again. Always test the URL in a regular browser first.
• Overlay shows a login prompt: you used the /events/[id]/live-feedadmin URL, which requires a session cookie. OBS can’t carry your login. Use the public display URL under /event/<CODE>/display instead.
• Overlay won’t go above PowerPoint full-screen slideshow on Windows: PowerPoint’s slideshow uses a topmost window. Use OBS’s Windowed Projector with a second monitor, or present in Slide Show > Set Up > Browsed by an individual (window) mode — the latter lets normal windows overlay it.
• macOS screen recording permission:if the projector window doesn’t appear on top, grant OBS Screen Recordingpermission in System Settings > Privacy & Security.