Wi-Fi answers

Chromecast / Google TV — smart-home gadget keeps going offline

Why does my Chromecast / Google TV smart device keeps going offline?

The short answer

The cast button vanishes from the phone even though the TV is switched on and online. On the WiFiXpert Compatibility Index the Chromecast / Google TV scores 64/100, and its weakest check is "Works on a guest network" — which is exactly where this problem comes from. Casting from a phone on the guest network fails.

Check the Chromecast / Google TV against your router

We publish what breaks with each router and mesh system, and the setting that fixes it.

Chromecast / Google TV — WiFiXpert Compatibility Index, 64/100
CheckVerdictPoints
Works on 2.4 GHzExcellent13/14
Works on 5 GHzSupported12/14
Modern Wi-Fi securityGood10/12
Happy on mesh Wi-FiGood11/16
Works on a guest networkPoor2/8
Survives a plug-in extenderWorks5/8
Doesn't depend on chatty discoverySignificant dependency6/16
Easy to fix when it goes wrongMedium5/12

The short answer

  • The cast button vanishes from the phone even though the TV is switched on and online.

What our compatibility data shows

  • Works on 2.4 GHz: Excellent
  • Works on 5 GHz: Supported
  • Modern Wi-Fi security: Good
  • Happy on mesh Wi-Fi: Good
  • Works on a guest network: Poor
  • Survives a plug-in extender: Works
  • Doesn't depend on chatty discovery: Significant dependency
  • Easy to fix when it goes wrong: Medium

Free fixes, in order

  • Put the phone and the Chromecast on the same Wi-Fi name.
  • Turn off any isolation or guest setting on the router.
  • Use the HDMI extender cable in the box so the dongle isn't buried behind the TV.

Before you spend anything

  • Rarely needed — this is almost always a network setting, not a signal problem.

People also ask

  • Does the Chromecast / Google TV work on mesh Wi-Fi?
  • Can I put the Chromecast / Google TV on a guest network?
  • Does the Chromecast / Google TV need 2.4 GHz?
  • Which router works best with the Chromecast / Google TV?

If you do end up spending money

Only after the free fixes. Nobody pays to appear here, and no shop link changes anything we say.

  • Router or mesh known to suit this device
  • A single wired connection to the device

Where this comes from

Related pages

Written by The WiFiXpert engineering teamUK Wi-Fi engineers, giq.ai Ltd.

Edited by WiFiXpert editorial desk.

Last reviewed 9 September 2026. Reviewed every 6 months, or sooner when a manufacturer or provider changes something.

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