Fix fullscreen on Wix websites

When you embed a Strimm channel player into a Wix website, the fullscreen button may not work. This happens because Wix sandboxes HTML embed blocks by default, which prevents the browser from granting fullscreen permission to the embedded player.

The fix requires enabling Wix Velo developer mode and adding one line of code to your site's master page. This is a one-time change and takes about five minutes.

Before you start: You need a Wix site with an HTML embed block containing your Strimm player. If you haven't embedded your channel yet, see Embedding your channel on your website first.

Step 1: Open your Wix site editor

Go to manage.wix.com, find your site in the list, and click Edit Site to open the Wix editor.

Step 2: Enable Developer Mode (Velo)

In the Wix editor top menu, click Dev Mode, then click Turn on Dev Mode. A code panel will appear at the bottom of the editor.

Wix editor showing the Dev Mode menu open with the Turn on Dev Mode button highlighted

Step 3: Find the ID of your embed block

Click on the HTML embed block that contains your Strimm player. You will see a small label in the top-left corner of the selected element showing its ID — for example #html1.

Make a note of this ID — you'll need it in the next step.

Wix editor with the HTML embed element selected, showing the #html1 ID label in the top-left corner of the element

Step 4: Open masterPage.js

In the code panel at the bottom, look at the left sidebar under Page Code. Click masterPage.js — this file runs on every page of your site.

Wix code panel showing the Page Code sidebar with masterPage.js highlighted, and the code editor open on the right

Step 5: Add the allowFullScreen line

Inside the $w.onReady() function, add the following line:

$w.onReady(function () {
    $w("#html1").allowFullScreen();
});

Replace #html1 with the element ID you found in Step 3. For example, if your embed block ID is html2, write $w("#html2").allowFullScreen();

masterPage.js with the allowFullScreen() line added on line 4 inside the $w.onReady function, highlighted in red
If there is already other code inside $w.onReady(), just add the new line alongside it — don't replace the existing code.

Step 6: Save and publish

Click Save in the top-right corner, then click Publish. Once published, open your live site and test the fullscreen button — it should now work.

Wix editor top-right area showing the Save and Publish buttons both highlighted with red boxes

Troubleshooting

  • Fullscreen still not working after publishing: Hard-refresh the page (Ctrl+Shift+R on Windows, Cmd+Shift+R on Mac) to clear the browser cache.
  • The element ID doesn't match: Click directly on the embed block in the editor. The ID shown in the top-left corner of the selected element is the correct one to use.
  • Multiple embed blocks on the site: If you have several HTML embed blocks, add a separate allowFullScreen() line for each one using their respective IDs.
  • Can't find masterPage.js: Make sure Dev Mode is enabled (Step 2). The code panel only appears after Velo is turned on.

Why this happens

Wix wraps HTML embed blocks in an <iframe> element. By default, this iframe does not have the allowfullscreen attribute, so the browser blocks fullscreen requests from inside it. The allowFullScreen() Velo method adds that attribute automatically when the page loads.

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