How to Set Up AlertForge Alerts in OBS

The short answer

AlertForge makes your alert videos. A connected alert widget, such as Streamlabs or StreamElements, listens for channel events and plays the right video. OBS displays that widget as a Browser Source.

A downloaded WebM does not listen for follows, subscriptions, or donations by itself. Adding it as an OBS Media Source is useful for a preview or manual playback, but it does not connect it to your channel's events. OBS explains this distinction in its alert setup guide.

Set up automatic alerts

1. Download your videos from AlertForge. Keep the transparent WebM files in their original format.
2. Connect your channel to an alert widget. Sign in to Streamlabs or StreamElements and check the supported events for your platform and account.
3. Upload the matching video for each event. Use the widget's custom-media setting. A raid video belongs on the raid event, for example.
4. Match the duration to the clip. Check entrance and exit timing so the widget does not cut the animation off.
5. Copy the widget's overlay URL. This URL comes from your alert provider, not the downloaded video. Treat private widget URLs like passwords.
6. Add a Browser Source in OBS. Paste the widget URL and match its canvas dimensions. Put it above gameplay in the Sources list.
7. Send a test event from the widget. Check the result in the OBS preview and a short recording before going live.

For platform-specific event notes, see the Twitch, YouTube, and Kick pages.

Add scenes, cam frames, and stingers

These files serve different purposes and use different OBS source types:

Asset	Where it goes
Animated Starting Soon or BRB scene	Media Source; enable Loop when you want repeated playback
Still scene or cam frame	Image Source
Stinger video	Scene Transitions, then Stinger
Event alert video	Custom media in your connected alert widget

For a manually triggered video, add a Media Source, turn Loop off, and choose whether playback restarts when the source becomes active. You can assign an OBS hotkey for manual playback. This is separate from automatic channel-event routing.

After replacing an alert in AlertForge, download the new WebM and upload it to your widget. An existing widget upload does not update automatically.

Fix common problems

• Nothing plays: test in the widget first. Check the channel connection, event assignment, and Browser Source URL.
• The alert is hidden: move the source above gameplay and confirm it is visible in the current scene.
• There is a black box: check that you used the transparent WebM, not an MP4 conversion. Remove any unnecessary colour-key filters.
• Sound is missing: confirm the video was generated with audio, then check the widget volume, OBS mixer, and output track.
• Sound plays twice: check whether both the video's audio and a separate widget sound are enabled.
• The animation cuts off: increase the widget's display duration to cover the full video.

Our transparent WebM guide explains alpha channels and file checks in more detail.

FAQ

Does playback use credits? No. AI generation uses credits; replaying a downloaded file does not.

Can I use the same files on different platforms? Yes, where the destination accepts the format. Each widget and platform controls which events can trigger them.

Do I need a chroma-key filter? Not for a correctly exported transparent WebM. Transparency is already in the file.

What should I test? Run every event you intend to use, switch scenes, and check a recording for placement and audio. A good preview in the builder does not replace testing your actual stream setup.

Sources

• OBS: Stream alerts
• OBS: Sources guide
• OBS: Media sources