If your stream alerts fire on screen but produce no sound, or you cannot figure out where alert audio even comes from in OBS, you are not alone. This guide walks you through exactly how to set up alert audio in OBS using the Browser Source method, covers an alternative approach for desktop audio, and includes quick fixes for the most common problems you will hit along the way.
How to Make an Audio Source for Alerts in OBS (Step-by-Step Guide)
How Alert Audio Actually Works in OBS
Alert audio is not a separate file you import into OBS. Services like StreamLabs and StreamElements deliver alerts as a Browser Source widget — a single source that contains both the visual overlay and the audio together. When you add that widget to OBS correctly, the audio comes with it automatically.
How Alert Audio Actually Works in OBS
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There is no standalone “alert sound” source to create; getting the Browser Source right is the entire job.
Step-by-Step: Setting Up an Alert Audio Source in OBS via Browser Source
Step 1 – Copy Your Alert Widget URL
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StreamLabs: Go to your StreamLabs dashboard, navigate to Alert Box under the Widgets section, and click Widget URL to copy the full link.
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StreamElements: Open your StreamElements dashboard, go to Alerting, and copy the Widget URL from that page.
Note: Use the full widget URL, not the URL from
your browser’s address bar while viewing the dashboard. They are different links and only the widget URL will work inside OBS.
Step 2 – Add a Browser Source to Your OBS Scene
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In the Sources panel at the bottom of OBS, click the + button.
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Select Browser from the list and choose Create new.
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Give the source a recognizable name (for example, “Alerts”).
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Paste your widget URL into the URL field.
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Set the width to 1920 and the height to 1080 as a baseline (adjust if your canvas is a different resolution).
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Check the box labeled Control audio via OBS. This step is critical — without it, the Browser Source will not appear as a channel in your Audio Mixer.
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Click OK.
Step 3 – Confirm the Source Appears in the OBS Audio Mixer
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Look at the Audio Mixer panel at the bottom of OBS. Your new Browser Source should now appear as its own channel.
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Right-click the channel and select Advanced Audio Settings.
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Find your Browser Source row and change the Audio Monitoring setting from Monitor Only to Monitor and Output. This ensures alert audio goes to both your stream and your local headphones or speakers.
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Adjust the volume slider to a level that sits comfortably below your microphone and game audio — somewhere between 60 and 80 percent is a reasonable starting point.
Step 4 – Test the Alert Audio Before Going Live
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Inside StreamLabs or StreamElements, locate the Test button next to your alert type (Follower, Subscriber, Donation, etc.) and click it.
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Watch the meter on your Browser Source channel in the OBS Audio Mixer. You should see it move when the alert fires.
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If audio monitoring is turned on, you should also hear the alert sound through your headphones or speakers.
Once you confirm both visual activity on the meter and audible playback, your alert audio source is set up correctly.
Alternative Method: Audio Output Capture for Desktop Alerts
Some third-party alert tools or browser-based setups play alert sounds through your system audio rather than through a widget. In those cases, you can route the audio using an Audio Output Capture source instead.
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In the Sources panel, click + and select Audio Output Capture.
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Name the source and select the output device your system uses for desktop audio (usually labeled “Default” or the name of your speakers or headset).
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Click OK and confirm the channel appears in the Audio Mixer.
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Apply the same Monitor and Output setting described in Step 3 above.
The trade-off here is real: Audio Output Capture picks up everything playing through that device, including music, system sounds, and browser tabs. You will need to keep other applications muted or managed carefully to avoid unwanted audio bleeding into your stream.
How to Put Alert Audio on Its Own OBS Track
If you record multi-track audio for VOD editing, isolating alert audio to a dedicated track lets you mute or remove alerts in post-production without touching your voice or game audio.
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In the Audio Mixer, right-click your Browser Source channel and select Advanced Audio Settings.
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In the Tracks column for the Browser Source row, uncheck all tracks except the one you want to dedicate to alerts (Track 3 is a common choice, leaving Track 1 for your mic and Track 2 for game audio).
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Make sure your other sources (mic, game capture) are not assigned to Track 3.
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In OBS Settings → Output, confirm that your recording format supports multiple tracks and that the correct tracks are enabled.
Your alert audio will now record to its own isolated track while your stream receives the full mixed output.
Troubleshooting: Alert Audio Not Playing in OBS
If alerts are visible but silent, or the Browser Source channel does not appear in the Mixer, work through these common causes:
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“Control audio via OBS” was not checked: Delete the Browser Source and re-add it, this time making sure the checkbox is enabled before clicking OK. There is no way to enable it after the fact without recreating the source.
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Audio monitoring set to “Monitor Only”: Open Advanced Audio Settings, find your Browser Source, and switch the setting to Monitor and Output. Monitor Only sends audio to your headphones but never to the stream.
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Browser Source channel is muted or at zero volume: Check the Audio Mixer for a mute icon or a volume slider sitting at the bottom. Click the mute icon to toggle it off, or drag the slider up.
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Alert widget URL is expired or invalid: Alert widget URLs can expire if you regenerate your overlay or change account settings. Return to your StreamLabs or StreamElements dashboard, copy a fresh widget URL, and update the Browser Source URL in OBS by double-clicking the source.
FAQ
Why can I see my alerts in OBS but hear no sound?
The two most likely causes are a missing “Control audio via OBS” checkmark when the Browser Source was created, or the audio monitoring being set to “Monitor Only” rather than “Monitor and Output.” Delete and recreate the Browser Source with the checkbox enabled, then update the monitoring setting in Advanced Audio Settings.
Do I need a separate audio file for OBS stream alerts?
No. Alert audio is embedded directly inside the Browser Source widget provided by StreamLabs or StreamElements. Adding the widget URL as a Browser Source in OBS brings in both the visual and audio together. You do not need to download or import any separate sound files.
Can I control alert volume separately from my microphone in OBS?
Yes. Each source in the OBS Audio Mixer has its own independent volume slider. Drag the slider on your Browser Source channel left or right to adjust alert volume without affecting your microphone, game audio, or any other source.
Does this work for both StreamLabs and StreamElements alerts?
Yes. Both platforms generate a Browser Source widget URL, and the setup process in OBS is identical for both. Copy the widget URL from whichever platform you use and follow the same Browser Source steps outlined above.
Conclusion
The Browser Source method is the fastest and most reliable way to get alert audio working in OBS. Once you have the widget URL added with “Control audio via OBS” checked and monitoring set to “Monitor and Output,” your alerts will play correctly on stream and in your headphones. Before going live, run a full test using the alert preview buttons in StreamLabs or StreamElements to confirm both the visual and audio are behaving as expected.
