Guide / Updated 24 October 2026
Why does browser noise stop when the phone locks?
Mobile browsers and operating systems decide how background audio behaves. They may suspend a web page when the screen locks, when another app takes audio or when power-saving rules apply. Source ↗
- A browser can be suspended after screen lock.
- Installing a PWA does not guarantee background audio.
- Test your actual device before relying on overnight playback.
How to try it
Test the exact phone and browser before bedtime. Keep the tab open, turn off battery-saving settings only if you are comfortable doing so, or use the SleepMix iPhone app for dedicated playback controls.
- Test the exact phone and browser before bedtime.
- Keep the tab open, turn off battery-saving settings only if you are comfortable doing so, or use the SleepMix iPhone app for dedicated playback controls..
- This generator cannot override system audio policy.
What to consider
This generator cannot override system audio policy. An installable PWA icon makes the page easy to reopen but does not guarantee locked-screen continuity.
What happens to a web page in the background
The generator uses Web Audio while its page is active. When the screen locks or another app takes focus, the browser and operating system decide whether that audio context continues, pauses or becomes interrupted. JavaScript cannot demand uninterrupted background time.
Apple’s WebKit issue history documents differences between Safari tabs, home-screen web apps and versions of iOS. That history is a reason to test the current device rather than promise that all iPhones behave identically.
A home-screen icon is not a native audio entitlement
Installing the PWA gives the page an icon and an app-like window. Its service worker can cache page files for an offline revisit, but the service worker does not keep the Web Audio worklet playing after the page has been suspended.
The MDN guide to offline and background operations explains that service workers may be stopped when inactive. Offline caching and continuous sound are different capabilities.
Test in the exact way you plan to sleep
Choose a short timer, press Play and lock the phone while you are awake. Leave it locked long enough to notice whether audio continues. Then unlock it and check whether the timer state and sound still agree. Repeat after connecting a Bluetooth speaker or changing browsers.
Also test notifications and phone calls if those commonly occur overnight. A route change can interrupt playback even when screen lock alone does not.
Choose a realistic fallback
If playback stops, use the browser for settling while the screen stays awake, then let the room become quiet. A dedicated iPhone app has a native audio session designed for longer playback; SleepMix is linked here for that use.
No app or website can promise that a depleted battery, disconnected speaker or device setting will never interrupt sound. Keep a separate alarm for an essential wake time.
Keep troubleshooting simple
Check that the browser was opened by a tap, device volume is up and the output route is the one you expect. If the page shows Play but no sound after an interruption, stop and restart it. Avoid repeatedly raising volume to compensate for a paused audio context.
If a browser update changes behavior, record the browser, iOS version and output device when contacting support. Those details are more useful than a vague report that the timer failed.
A short test before bed
Open the page. Press Play. Lower the sound. Lock the phone for a few minutes. If you still hear it, unlock and try a call or alert. This simple test tells you far more than a claim that all phones work the same way. If the sound cuts out, plan to use the tool only while you settle.
Common questions
Will adding the site to my home screen fix this?
It can make the tool easier to reopen, but it does not override the operating system’s audio policy.
Why does it work in one browser but not another?
Browser engines, device settings and audio routing differ, and their behavior can change after updates.
What is the dependable workaround on iPhone?
A dedicated app such as SleepMix is designed for a native audio session; still test your device before an important night.