Stream alerts are the on-screen popups that play when someone follows, subscribes, donates, or cheers bits. They give the streamer a moment to acknowledge the supporter on stream and give the audience a small celebration.
Setting up alerts takes about 30 minutes the first time. Most of that is decisions about what to alert on and how loud the alert should be, not technical work.
The three pieces
An alert system needs three components:
- An alert service. The service that watches your channel for events and produces the alerts. An overlay tool with an alert widget, or Twitch's built-in alerts, are the standard options.
- A browser source in OBS pointed at the alert service's widget URL.
- An OBS scene that includes the browser source on top of your other content.
You only need one alert service per channel. Picking one and using it consistently saves a lot of debugging later.
Choosing an alert service
For a new streamer, the practical choice is an overlay tool with built-in alert support or Twitch's own built-in alerts.
A good overlay tool includes an Alert widget that covers follows, subscriptions, bits and raids, and generates a browser source URL you paste directly into OBS once the widget is configured.
Twitch's built-in alerts require no additional software and are managed from the Twitch Creator Dashboard. They are limited in visual customisation but need no external service.
Setting up the alert widget
For an overlay tool with a widget-based alert system:
- Open the tool's dashboard and find the widget or alert section.
- Create a new widget and choose Alert as the type.
- Configure the appearance for each alert type: follow, subscription, bits, raid.
- Copy the browser source URL from the widget card.
- Do not share the URL publicly; it is tied to your account.
The widget dashboard also lets you trigger test alerts. Test each type after configuring it.
Adding the alert source to OBS
In OBS:
- Right click in the Sources panel, then Add, then Browser source.
- Name it "Alerts" or similar.
- Paste the widget URL.
- Set width to 1920, height to 1080. The widget itself handles positioning within that frame.
- Tick "Shutdown source when not visible" to free CPU when the scene is not active.
- Click OK.
The Alerts source should be at the top of the Sources panel for that scene, so it draws on top of everything else.
If you have multiple scenes, you can either add the same source as a reference in each scene where you want alerts (preferred; one configuration, one CPU cost), or add separate browser sources in each scene with the same URL (works, slightly more configuration). Use the reference approach unless you have a reason not to.
Volume
Alerts are usually too loud out of the box. Test in OBS by triggering a test alert and watching the audio meter for the alert source. Aim for the alert volume to be quieter than your voice. The alert should be audible but not jarring.
If the alert is hard to hear over your game, the answer is almost always lower game volume in OBS, not louder alerts. A loud alert pattern is exhausting at hour three of the stream.
Designing alerts that work
A good alert pattern:
- Is short. 2 to 4 seconds maximum, including the read.
- Has visual variety. Different sub tiers, different gift sub amounts, different follow vs sub vs raid. Each should look distinct.
- Is quiet enough to talk over without raising your voice.
- Skips for spam events. If 50 follows arrive in 60 seconds (a hate raid pattern), alerts that play 50 sounds in a row are a problem. Configure a follow alert cooldown.
Avoid:
- A single long alert pattern (10 seconds or more) for every event. The viewer's first 50 follow alerts will be charming. The next 5,000 will not be.
- Alerts that play recorded voices reading the supporter's name. Sounded clever once. Sounds dated now and is hard to design well.
- Alerts that use copyrighted music. YouTube and TikTok will claim the audio on clips later.
Resub messages and gifted subs
For subscriptions, two specific events are worth designing carefully:
- Resub alerts. When someone resubs (renews their sub), Twitch lets them post a message with the alert. Display this on screen with the alert if your audience is small enough to read it.
- Gifted sub alerts. When someone gifts multiple subs at once (5, 10, 50), the alert should aggregate rather than play once per sub. Check this setting in your alert tool.
Things that break alerts
Three issues that come up frequently:
- The alert worked yesterday but is silent today. The browser source token has expired, or you logged out of the alert service. Re-paste the URL in the browser source.
- The alert plays but is blank. The widget URL is wrong, or the alert service is down. Test in a regular browser tab.
- The alert is delayed by 5 seconds or more. The stream has lag (this is normal; alerts and game audio do not always sync). Live, this is fine.
What does not need alerts
Some events do not need alerts at all:
- Channel point redemptions. Twitch handles these natively.
- Viewers joining or leaving. Most viewers will hate notifications for every join.
- Predictions opening or closing. Twitch overlays these on the stream itself.
Most streamers should have alerts for follows, subs, bits over a threshold, raids, and gift subs. That is the full list.
Backup plan
Alerts break. The alert service has occasional outages. A stream where alerts are silent is fine. A stream where you assume alerts are working and they are silently not is not fine.
A simple safety net: every 30 minutes, glance at the alert service's dashboard in another browser tab to confirm events are being recorded. If alerts stop appearing and the dashboard still shows events, refresh the browser source.