Screen Wake Lock Tester - Online Keep Screen On
Toggle a screen wake lock to prevent the device from dimming or sleeping. See the lock state and learn the API.
UD5 Toolkit
Test the Screen Wake Lock API — Prevent Your Screen from Sleeping
Note: The API requires a secure context (HTTPS or localhost) to function. Most modern Chromium-based browsers fully support it.
Toggle a screen wake lock to prevent the device from dimming or sleeping. See the lock state and learn the API.
Set a nap timer with optional gentle white noise or lullabies (Web Audio). Reminder to put baby down. Fully local, no ads.
Log daily sleep to see cumulative sleep debt or surplus over weeks. Visualizes chronic sleep loss trends. Stores data locally in your browser only.
Configure how your PWA launches: focus existing or create new. Test with the launch_handler manifest field.
Compress and decompress text using the browser's native Compression Streams API. See the binary output size.
Query the permission state of camera, microphone, geolocation, and more. See the response and learn the API.
Unified input demo: see pressure, tilt, and type from any pointer. Compare pointerType values. Essential for drawing apps.
Decode an image progressively using the ImageDecoder API. See partial results and metadata. Modern alternative to <img>.
Decode individual video frames from a local file using the VideoDecoder API. Step through frames. Cutting‑edge browser feature.
Experiment with the Federated Credential Management API. Simulate a sign‑in flow without third‑party cookies. Privacy‑first.
Request HID devices and list them. Read input reports and send output. For custom hardware and controllers.
Request permission and detect when the user is idle (away from keyboard). See screen lock state. For native‑like apps.
Demonstrate how the Web OTP API automatically reads one‑time codes from SMS (mobile). Simulation with a fake SMS input.
Acquire and release locks across tabs. Prevent race conditions in IndexedDB or localStorage. Visual queue and lock state.
Connect a gamepad and see all button presses and axis movements visually. Check that every input is detected correctly.
Trigger different vibration patterns on mobile devices. Test if your phone supports haptic feedback. Simple demo.
See your device's battery level, charging status, and discharge time using the Battery Status API. Fun utility.
Check current screen orientation and test the lock API. Useful for mobile web apps. Demo with code.
Test the new HTML popover attribute for creating accessible tooltips, menus, and dialogs without JavaScript. Copy code snippets.
See the View Transitions API in action. Cross‑fade and morph between two states. Copy the JavaScript starter code.
Experiment with the Async Clipboard API: read/write text and images from the clipboard. Verify permissions and see demo code.
Test the Web Share API by sharing text, links, and files directly from the browser. Check compatibility and see example code.
Enter an API URL and quickly check its HTTP status code and response time. See response headers and body. Browser fetch.
Pick a method, URL, headers, and body, then send an HTTP request directly from your browser. Debug APIs easily.
A completely black page to save battery on OLED devices. Click to go fullscreen. Simple utility.
Turn your browser screen into a full‑color flashlight or strobe. Adjust brightness and color. Simple utility.
An on‑screen ruler that measures in pixels, centimeters, and inches. Drag to resize. Handy for UI designers and developers.
Generate random JSON data with customizable fields (users, products, orders). Useful for frontend mocking. All local.
Execute GraphQL queries against any endpoint with variables and headers. Explore schema via introspection. All requests made directly from your browser.
Display detailed information about your current browser, including version, JavaScript status, cookie support, and screen size. Works instantly with no input.