Fullscreen API Tester
Test the Fullscreen API, check support and toggle full-screen mode from your browser.
How to use this tool
- Open this page — it runs instantly in your browser, no signup or install.
- Allow any permission prompt if asked; everything stays on your device.
- Use the on-screen controls — results update live.
Test the Fullscreen API, check support and toggle full-screen mode from your browser.
Frequently asked questions
- Why does fullscreen not work?
- Browsers require a user gesture (click) to enter fullscreen. It also cannot be triggered on load or from an iframe without the allow='fullscreen' attribute.
- How do I exit fullscreen with the keyboard?
- Press Escape to exit fullscreen in all browsers.