Fix Fullscreen Not Working in Chrome, Edge, or Safari (Run the Screen Test)

Confirm fullscreen behavior with the Screen Test

Start by verifying that fullscreen works in your browser at all (before blaming the website). Open the Screen Test and click Toggle fullscreen.

If fullscreen enters, the page should update with a new Viewport value (width × height). If nothing changes, fullscreen is being blocked by a shortcut conflict, OS restriction, or browser/extension issue.

In this guide, you’ll:

• Confirm fullscreen works on a neutral page (Screen Test)
• Fix the common blocks (shortcuts, extensions, focus issues)
• Re-test on the site that failed

Quick answer (fastest path)

1. Test fullscreen on Screen Test
2. Try fullscreen with extensions disabled (Incognito/InPrivate)
3. Restart the browser and try again
4. If you’re on a work device, check for managed restrictions

Fix 1: Use the correct fullscreen method for your situation

There are two different “fullscreen” modes, and people often hit the wrong one:

• Browser fullscreen: expands the entire browser window
  • Windows/Linux: F11 (or Fn + F11 on some laptops)
  • macOS: Control + Command + F (or the green window button)
• Video/player fullscreen: expands only the video player (the ⛶ icon on the player)

If the player’s fullscreen button fails, try browser fullscreen (F11). If browser fullscreen works but player fullscreen fails, the issue is likely the site’s player, an embedded iframe, or an extension that modifies the page.

Fix 2: Remove keyboard and focus conflicts (the “instantly exits” problem)

Fullscreen requests can fail if the page loses focus or if a shortcut immediately triggers Esc behavior.

• Click inside the page, then click the fullscreen button again (some sites require a direct user gesture).
• Avoid switching windows right after clicking fullscreen.
• If you use an external keyboard, try the built-in keyboard once (some function keys map differently).
• Close overlays that can steal focus (password manager popups, translation popups, picture-in-picture).

Re-test on the Screen Test. If it now works there, go back to your original site.

Fix 3: Disable extensions that inject UI or modify video players

Fullscreen and video players are common extension breakpoints.

Test without extensions:

1. Open an Incognito/InPrivate window (extensions off by default)
2. Go to the Screen Test and your failing site
3. Try fullscreen again

If fullscreen works with extensions off, likely culprits include:

• Ad blockers in advanced modes
• Script blockers and privacy suites that rewrite page content
• Screen recorders and “video downloader” extensions
• Accessibility tools that inject overlays

Keep the extension installed if you need it, but allowlist the affected site so it stops injecting scripts into that page.

Fix 4: Restart the browser (and update if needed)

Fullscreen can fail after graphics resets, sleep/wake cycles, or long-running sessions.

• Restart the browser completely (close all windows, then reopen).
• Update your browser if it’s behind:
  • Chrome/Edge: Menu > Help > About → update → Relaunch
  • Firefox: Menu > Help > About Firefox → update → restart

Then repeat the Screen Test fullscreen toggle.

Fix 5: Fix black bars, wrong monitor, or “zoomed” fullscreen

If fullscreen works but looks wrong (cropped, black bars, wrong display), isolate whether it’s the browser, the OS, or the site.

1. Use the Screen Test in fullscreen and note the viewport size.
2. Move the browser window to the monitor you want, then enter fullscreen again.
3. Check OS display settings:
   • Ensure your external display is set to its native resolution
   • Avoid extreme display scaling during testing

For video black bars specifically: they are often normal aspect-ratio behavior (a 16:9 video on an ultrawide display will show bars). If the bars are excessive or the picture is blurry, see our Blurry Text or Zoomed Pages guide.

Fix 6: Managed devices and kiosk restrictions

On managed devices, fullscreen can be limited by policy or kiosk configuration.

• If you’re on a work profile, check if the browser is managed (Chrome/Edge menus often show “Managed by your organization”).
• Try fullscreen on a personal device or a different browser to confirm it’s policy-related.
• If policy is the cause, share your Screen Test behavior with IT and request an exception for the affected site/app.

Verify the fix

1. Re-run fullscreen on the Screen Test and confirm viewport changes.
2. Return to the site that failed and try:
   • Player fullscreen
   • Browser fullscreen (F11 / Enter Full Screen)
3. If the site still fails but the Screen Test works, the issue is site-specific (player code, embedded iframe, or account-level restrictions).