Test alerts and check OBS delivery

Choose the test that matches your source

Every alert test starts from the alert itself: open Overlays, open the overlay and click its alert layer. The panel has two tests, and they go to different places.

You want to check	Use	Reaches OBS?
How the design looks	Test in editor in the alert panel, or Test on the layer’s toolbar	No — the editor’s canvas only, with your draft
That OBS shows it	Test published output…, then Play it on stream	Yes, through the real alert queue — viewers may see it. It uses the published design; check the result in OBS
Every alert on one overlay	Simulate in the top bar → Test events	Only if you tick Also play on the live overlay in OBS
That your flow’s checks pass	Test fire in the flow editor	No — a dry run
Your own HTML widget	Test published output… on any alert layer (below)	Yes, to every connected source that takes alerts

None of these posts to Twitch chat. Show alerts on stream covers setting alerts up; this guide is about checking that they arrive.

Send an alert to a custom overlay

On Overlays → Custom overlays, choose the named overlay. Grant stage.alert and the matching alert_design:name record under Data access. Your page must subscribe to stage.alert with the Overlay SDK.
Keep its OBS scene visible, then press the refresh icon (Refresh status). The named overlay should show a connected source.
Open an overlay design, select an alert layer and press Test published output…, then Play it on stream.
Watch OBS. The test joins the alert queue and reaches your custom overlay. It does not send a Twitch event or run the flow.

See Connect your own HTML overlay for setup. Grant and subscribe to other event types separately when your page draws them.

Test a hosted overlay

In OBS, make the scene with the overlay’s Browser Source visible. Its URL comes from OBS URL in the editor’s top bar.
In the editor, check the chip in the top bar reads Published. For pending designs, press Publish, review the named changes and affected overlays, then confirm Publish. Unticked parts stay in your draft: OBS uses only published designs. Published does not confirm that the source is showing in OBS.
Select the alert layer, press Test published output… and confirm with Play it on stream.
Read the sentence under the button and watch OBS.

Playing now on your overlay. reports the queue’s playback state; it does not prove that OBS displayed or played it. Check your streaming app. Queued — number 2 in line. means other alerts were ahead of it. Queued, but no overlay open in OBS right now shows the raid design means no open Browser Source has a layer for that design: check the scene is visible and the source has the current URL. OBS does not have the raid design yet means it is only in your draft — publish, then test again.

The alert workspace’s Published output disclosure separates that queue reply from the selected overlay’s evidence. It shows the published overlay revision, historical load marks and latest channel test for the design. Source connection and Visible or audible playback stay Unknown: a historical OBS load does not prove a connection now, and an accepted test frame does not identify its receiving overlay or version. Use Refresh output evidence to check again, or retry a failed check, then confirm the picture and sound in OBS.

The Live page’s Alerts card shows the same test as Test · raid, playing or up next, Waiting for an overlay with alerts in OBS while nothing that shows alerts is open, Held: your overlay is hidden in OBS while the overlay is open but its source is hidden, and alerts held: no open overlay shows the design … when the overlays you have open have no layer for that design.

Check the behaviour separately

A test from the alert panel plays the design itself: it does not run the flow, so the flow’s checks — a minimum number of bits, a moderators-only command — are not tested by it. Use the flow editor’s Test fire for those: it runs the flow on a made-up event and its Run log says whether it “would play” the alert, without sending anything to Twitch or your overlay. To change what plays an alert, use Plays on in the alert panel, or Open flow on one of its rows.