Last updated: 22 August 2026
The short answer
Alerts do not come from OBS. They come from an alert service — Streamlabs or StreamElements — which watches your Twitch events and produces a single web page. OBS just displays that page.
- Sign in to Streamlabs or StreamElements with your Twitch account.
- Open the Alert Box widget and configure which events you want.
- Copy the widget URL.
- In OBS, add a Browser source and paste that URL. Leave Local file unticked.
- Set the size to your canvas resolution (usually 1920×1080) and position it.
One Browser source handles every alert type. You do not need a separate source per event.
Why it works this way
Only a service authorised on your Twitch account can know that someone just subscribed. OBS has no connection to Twitch's event system — it renders video. So the alert service does the listening and the drawing, and hands OBS a URL.
This is also why alerts keep working when you switch computers: the configuration lives in your alert service account, not in OBS.
Setting up the alert box
Streamlabs
Go to Alert Box in the dashboard. Each event type — Follows, Subscriptions, Cheers, Donations, Raids — is configured separately: image, sound, message format, duration.
Two settings worth changing from default:
- Alert duration — the default is often longer than it needs to be. Three to five seconds is usually plenty.
- Alert delay between alerts — raise this slightly so a burst of follows queues rather than overlapping.
StreamElements
Open your overlay, then the Alertbox widget. Same idea, configured per event type in the left panel. Your overlay URL is what goes into OBS.
Installing a custom alert pack
If you have bought an alert pack, the files are the animations and sounds — you upload them into your alert service, not into OBS.
Streamlabs
Some packs ship as an importable widget theme. In Alert Box → Settings, scroll to the bottom and use Import Widget Theme, then select the .zip. Everything applies at once.
Otherwise, upload each animation to its matching event type manually.
StreamElements
Upload per event type: choose the alert type, then upload the matching file for follow, subscribe, cheer, donation and raid.
Adding it to OBS
Click + in Sources, choose Browser, and name it "Alerts". Paste the widget URL. Leave Local file unticked — this is a hosted page, not a file on your computer.
Set Width and Height to your canvas size rather than a small box. The alert service positions alerts within that area, so a full-canvas source lets your configured positioning work as intended.
Put the Alerts source at or near the top of your source list so alerts draw over everything else.
Common problems
The test alert works but real events never fire
The most common alert problem, and it is almost never OBS. Either the alert service lost its Twitch authorisation — reconnect your account in the service's settings — or you are testing on a different overlay to the one whose URL is in OBS. Confirm the URL in OBS matches the overlay you are editing.
Alerts overlap into a mess during a raid
Raise the delay between alerts so they queue.
No sound
Check the alert's volume in the service, then check OBS is not muting the Browser source in the Audio Mixer. Browser sources have their own audio channel.
The alert box is blurry or cropped
The Browser source dimensions do not match the overlay's design resolution. Set both to 1920×1080.
Alerts stopped after a scene switch
Turn off Shutdown source when not visible for the alerts source.
FAQ
Do I need both Streamlabs and StreamElements?
No. Pick one. Running both alert boxes at once causes double alerts.
Can I use alerts on Kick or YouTube?
The alert services support other platforms, though feature coverage varies. The OBS side is identical.
Do alert packs work with either service?
Generally yes — ours ship files for both. Check what a pack includes before buying.
What is the difference between an alert and a widget?
An alert fires on a Twitch event and disappears. A widget is a persistent browser source that can react to chat and live data. See what are Twitch widgets?