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Guide · 4-minute read

Chrome Energy Saver and wake locks: why the screen still goes dark

You can leave Chrome's Energy Saver on. It slows tabs in the background, and Chromium's wake lock code has no check for it, so a visible tab still keeps the screen on. If the screen goes dark anyway, the tab was hidden, or a setting outside Chrome took over. The steps below find which one.

Sources checked Saturday, 26 September 20264 min readBy Soubhik Biswas
Start a 30-minute session

Find the real cause in five steps

These work in Chrome and Edge on any system. Sources checked 26 September 2026: Chromium's wake_lock.cc refuses only for a hidden or inactive page, a Permissions-Policy block or a denied permission, and never reads a saver mode.

0 of 5 done

  1. Step 1 · Bring the AwakeTab tab to the front

    Next upChrome › the AwakeTab tab

    Energy Saver slows background tabs, and a hidden tab has no wake lock anyway. Switching tabs or minimising the window releases the lock. A visible window without focus keeps it.

  2. Step 2 · Start a session and read the pill

    AwakeTab › Start

    Wait for "Screen awake", which shows only once Chrome has granted the lock. If it says "Blocked — here's the fix", follow the line under it.

  3. Step 3 · Check the Windows screen timeout and Energy saver

    Settings › System › Power & battery

    Windows keeps one screen timeout for battery and one for plugged in. Energy saver (Battery saver before Windows 11 24H2) may shorten timeouts or dim the screen on battery, but it does not refuse a browser wake lock.

  4. Step 4 · Check the phone's own timeout

    Settings › Display › Screen timeout

    On a Pixel with Android 16, the path is Settings › Display & touch › Screen timeout. Battery Saver may shorten it or dim the screen, but Chrome does not refuse the lock because of it.

  5. Step 5 · Confirm the request reached the system

    Terminal › powercfg /requests or pmset -g assertions

    On Windows, run powercfg /requests in an administrator terminal: the browser should be listed under DISPLAY. On a Mac, run pmset -g assertions and look for a PreventUserIdleDisplaySleep or NoDisplaySleep line from your browser.

If the screen still goes dark

With the tab in front and the pill saying "Screen awake", the cause is outside the browser. These are the usual ones.

  • The lid closedA closed laptop lid sleeps the computer whatever a page asks, apart from a Mac in clamshell mode or a Chromebook with "Sleep when cover is closed" turned off.
  • A work lock screen appearedA wake lock holds off display sleep, not a "require sign-in after N minutes" policy. On a work computer, only your IT team can change it.Lock screen versus sleep
  • The session endedA timed session stops at the time you picked, and your normal timeout takes over. Pick ∞ to run until you stop it.

What each saver changes

Four different switches share the name. None makes Chrome refuse a wake lock, but some change what the system does around it.

  • Chrome's Energy SaverSlows tabs in the background. It does not touch the wake lock of the tab you are looking at.
  • Windows Energy saverCalled Battery saver before Windows 11 24H2. It may dim the screen or shorten timeouts; it does not refuse a browser wake lock.
  • Android Battery SaverChrome has no Battery Saver check on the wake lock. It may shorten your timeout or dim the screen once you leave the tab.
  • iPhone Low Power ModeSets Auto-Lock to 30 seconds. WebKit has no Low Power Mode check; whether a Safari lock holds under it has not been device-tested yet.iPhone Auto-Lock greyed out

To keep the screen on while you work in another tab, use AwakeTab for Chrome on desktop Chrome or Edge.

Try it hereOr skip the settings: open AwakeTabYou don't need to turn Energy Saver off first. Keep this tab in front and press Start: the pill says "Screen awake" once Chrome grants the lock, and it changes to "Paused — tab hidden" the moment the tab is out of sight. Ends at … if you start now.Start a 30-minute session

Questions

No. Chromium's wake lock code has no check for Energy Saver, and the lock permission is allowed by default. Turning it off changes how background tabs behave, not whether the visible tab can keep the screen on.

Soubhik Biswas · Builds AwakeTab. Sources checked Saturday, 26 September 2026. About AwakeTab