There are two different things people mean by a Twitch alert box background, and they need different setups. The first is a backdrop behind the alert card itself - the panel that shows "NewViewer just subscribed". For that, add Vortexia as a Browser Source in OBS and place it directly beneath your alert box source in the same scene, sized to the alert area rather than the full canvas. The second, and the one most people actually want once they see it, is the whole screen reacting when an event lands. Vortexia connects to Twitch or Streamlabs and gives each event its own treatment: a raid pulls the camera back and sends a bright band outward, a hype train holds a sustained swirl for as long as the train runs, bits sparkle, a donation shakes the frame and rings a golden ripple, and a follow is a soft ripple - deliberately the gentlest, because if small events feel big then big events stop feeling big. Alert widgets like StreamElements and Streamlabs know about the events but draw a card in a corner; audio visualizers drive the whole screen but have no connection to Twitch and cannot know a raid happened. Running Vortexia underneath your existing alert box gives you both. Free at 720p with a small watermark; Plus is $4.99 a month.
Add the Browser Source. In OBS, add a Browser Source with your viewer URL. For a full-screen reaction use 1920x1080; for an alert-box backdrop, size it to the alert area instead.
Order your sources. Place it directly beneath your alert box, or at the bottom of the scene for a full-screen effect.
Rehearse each event. Fire every treatment once from the dashboard buttons so nothing surprises you mid-stream.
Specs & output
Engine
Chaos Prime
Render Mode
genesis
Iteration Depth
50
Default Zoom
0.80
Colour Shift
260°
Output (Free)
720p / 30fps + watermark
Output (Plus)
1080p / 60fps, no watermark
Output (Pro)
4K / 60fps, brand-kit logo overlay
Audio Source
Browser tab audio (FFT, real-time)
Last Updated
2026-08-24
Frequently asked questions
Should this replace my StreamElements or Streamlabs alerts?
No - run both. Your alert box names the person and plays your sound; Vortexia changes the background around it. They occupy different parts of the screen and different jobs, and most setups keep the card and put the reactive backdrop behind it.
How do I put it behind just the alert box rather than the whole screen?
Add the Browser Source in the same scene, drag it directly below your alert box source in the list, and resize it to cover only the alert area. For a full-screen reaction instead, size it to your canvas and put it at the bottom of the list.
Which events change the visual?
Subscriptions, gift subs, cheers or bits, follows, raids, and all three hype train stages, plus donations through Streamlabs. Each has its own treatment rather than one shared flash.
Can I test the reactions before going live?
Yes. The dashboard has manual trigger buttons for sub, donation, raid, hype train, bits and follow, plus Shift+Alt+1 to 6 keyboard shortcuts for the same. Meeting an effect for the first time in front of an audience is not the moment to find out you dislike it.
Does it need my Twitch login?
To react to real events, yes - one OAuth connection in the Platforms tab, which registers the EventSub subscriptions for you. Without connecting, everything still works as an audio-reactive background and the trigger buttons still fire effects manually.
About the author
Yousef @ Vortexia — Vortexia Engine Creator.
Yousef builds Vortexia — a browser-based, GPU-accelerated audio-reactive visual engine used by streamers and DJs on Twitch, Kick, YouTube Live and TikTok Live.