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Look at the TV before you look at your phone
Switch the TV to the Chromecast's HDMI input and see whether its own home or ambient screen appears. If it does, the device is powered, connected and on the right input — your problem is between your phone and it, which means the network. If the screen is blank or shows a low-power warning, stop troubleshooting the network entirely: the most common cause is a Chromecast powered from the TV's USB port instead of its own mains adapter, which Google explicitly says may not supply enough power.
Applies to: Chromecast, Chromecast Ultra, Chromecast with Google TV and the Google TV Streamer, casting from Android, iPhone, iPad and the Chrome browser. Menu names differ slightly between the Google Home app versions; the current ones are used below.
What is on the TV?
A Chromecast that won't show up is almost never broken. It is usually underpowered, on a different network from the phone you are casting from, or sitting behind a router setting that blocks devices from seeing each other. Those causes look identical in the Google Home app — the device simply is not there — but they are trivially separated by looking at the television first. Do that, then follow the branch it puts you on.
The TV shows nothing or a low-power warning
Is it powered from the TV’s USB port?
Fix the powerIt works on the TV but the phone can’t see it
Are both on the same Wi-Fi network name?
Check the networkSome phones find it and others don’t
Is AP isolation switched on at the router?
Check the routerThe cast button has disappeared entirely
Does the app have local network permission?
Check permissions1. Power is the first thing to rule out, not the last
Google's guidance is unusually direct on this point: the Chromecast should be plugged into the power adapter that came with it, because plugging it into the TV's USB port or a different adapter might not supply enough power. For Chromecast Ultra the wording is stronger still — you must use the power supply included in the box, and it will not work with any other USB cable or a USB cable plugged into a TV.
This matters because TV USB ports look like a tidy solution and behave badly. They frequently cut power in standby, and many supply less current than the device needs under load, which produces a fault that follows no pattern: the Chromecast works until something demanding happens, then drops off the network and vanishes from the app. Google publishes a dedicated troubleshooting page for the Low power and g.co/cast/power screens for exactly this reason.
Check the LED as well. A white light that flashes indicates the device has power and is in the expected state, and Google's setup troubleshooting has you confirm this before anything else. No light at all, on the supplied adapter in a wall socket, points at the adapter, the cable, or the device — and swapping the adapter is the cheapest of those to test.
If the Chromecast has been running from a TV USB port for months without trouble, that does not clear it. This failure appears when the TV’s firmware changes its standby power behaviour after an update, which is why it can start suddenly with nothing else having changed.
2. Same network — and same network name
Casting works by devices finding each other on a local network, so both ends have to be on the same one. Google states it plainly: Chrome cannot find Google streaming devices on different networks, and your phone and the Chromecast must be connected to the same wireless network name. This sounds obvious and catches almost everyone, because modern routers make it easy to be on the wrong one without noticing.
The specific traps are worth naming. Many routers broadcast 2.4 GHz and 5 GHz under separate names, so a phone on the 5 GHz network cannot see a Chromecast on the 2.4 GHz one. A guest network is worse — it isolates clients from each other by design, so a phone connected to it will never find anything. And a phone that has silently fallen back to mobile data, or is connected to a VPN, is effectively on a different network too. Turn the VPN off and confirm the Wi-Fi name on the phone matches the one the Chromecast uses.
If your Wi-Fi name is hidden, the device needs it entered by hand. Google's setup guidance covers this: tap Other during setup and supply the network name and security type — WEP, WPA or WPA2 — rather than expecting the device to discover it.
Split bands
A phone on the 5 GHz network cannot see a Chromecast on the 2.4 GHz one when the two bands have different names.
Guest network
Guest networks isolate clients from each other by design. Nothing on one will ever find a Chromecast on the main network.
3. The router setting that hides everything
If the phone and the Chromecast are demonstrably on the same network and still cannot see each other, suspect AP isolation. It is a router feature — sometimes called client isolation, AP isolation, or station isolation — that stops devices on the same Wi-Fi network from communicating with one another. It is a sensible default on a public hotspot and a disaster on a home network, and Google's troubleshooting names disabling it directly.
It is also switched on more often than people expect: some ISP-supplied routers enable it by default, and it can be turned on inadvertently by a guest-network or security wizard. Look for it in the router's wireless or advanced settings. The signature is distinctive — everything has internet access and works perfectly, but no device can see any other device, so printers, speakers and Chromecasts all disappear at once.
Google also mentions firewall features on the router that block incoming connections to Cast-enabled devices, which produce the same symptom through a different mechanism. If you have set up any firewall rules, VLANs or IoT-segregation on your network, the Chromecast and the phone need to be able to reach each other rather than merely both reach the internet.
The tell for AP isolation is that nothing on the network can see anything else — not just the Chromecast. If your printer also vanished, stop troubleshooting the Chromecast and go to the router.
4. When the phone is the problem
Phone-side permissions break casting in a way that gives no useful error. On iPhone and iPad, the app needs Local Network access — without it, the app genuinely cannot see devices on your Wi-Fi and the cast button simply never appears. Google's troubleshooting calls this out along with having Bluetooth switched on for iPhones during setup. Check it under Settings → Privacy & Security → Local Network, and confirm the app you are casting from is enabled, not just the Google Home app.
On Android the equivalent is location services, which older versions require for the network discovery casting depends on. Google's guidance names enabling location for Android Marshmallow devices, and the underlying requirement persists in various forms on later versions. Also make sure the Google Home app and Google Play services are both current — Google lists updating both as a step, and an out-of-date Play services is a real cause of devices not appearing.
One genuinely obscure cause worth knowing because nothing else explains it: Google's troubleshooting includes checking whether your computer's clock is out of sync with internet time. A significant clock offset breaks the encrypted handshake casting uses, and the failure presents as the device simply not being found. If you are casting from a desktop that has been off for a long time or has a failing CMOS battery, check the clock before anything else.
5. Reboot everything, in the right order
Google's reboot procedure has an order and it is worth following rather than improvising. Unplug the streaming device's power cable, wait a few seconds, plug it back in, and give it a couple of minutes to come back. Separately, power the router off by unplugging it, wait several seconds, and plug it back in — then let it fully restart, which takes a couple of minutes on most routers, before testing.
Close and reopen the Google Home app rather than just switching away from it, and toggle Wi-Fi off and on again on the phone. Both force fresh network discovery instead of reusing a cached result, and a stale cache is a common reason a device stays missing after the underlying problem has been fixed.
Distance matters during setup specifically. Google's guidance is to keep the phone within 15 to 20 feet — four to six metres — of the streaming device while setting it up, and to have the device near the router with a strong signal. A Chromecast behind a wall-mounted TV with a metal bracket is in a genuinely difficult spot for radio, and a device that works when held near the router and not when installed has told you what the problem is.
6. Factory reset, and what to tell support
A factory reset is Google's last step and it should be yours too. It clears the device's stored network credentials and returns it to setup state, which fixes a Chromecast holding an old Wi-Fi password after a router or ISP change — a common cause of a device that worked for a year and then vanished. On most models the reset is a button on the device held until the LED changes; check Google's instructions for your specific model rather than guessing, since the behaviour differs.
Reset only after the network side is confirmed, though. A reset on a device that is underpowered or sitting behind AP isolation will simply fail to complete setup, and you will have lost the configuration for nothing. The order in this guide is deliberate for that reason: power, network, router, phone, reboot, and only then reset.
When you contact support, lead with what the TV showed, because it splits the problem in two before anything else. Tell them whether the Chromecast's own screen appears on the TV, what the LED does, whether it is powered from the supplied adapter or a TV USB port, whether the phone and device are on the same network name, and whether any other device on your network can see any other. Those five answers separate a power fault from a network configuration from a device that genuinely needs replacing.
Frequently asked questions
Why is my Chromecast not showing up?
Check the TV first. If the Chromecast's own screen appears on its HDMI input, the device is fine and the fault is on the network side — usually the phone being on a different Wi-Fi name, a guest network, or AP isolation at the router. If the TV shows nothing or a low-power warning, it's a power problem, and the usual cause is running it from the TV's USB port rather than its own adapter.
Can I power a Chromecast from my TV’s USB port?
Google advises against it — the guidance is to use the adapter that came with the device, because a TV USB port or a different adapter might not supply enough power. For Chromecast Ultra it's stricter: you must use the supplied power supply, and it won't work with a USB cable plugged into a TV. TV USB ports often cut power in standby and under-supply current, which produces dropouts that follow no pattern.
Why can’t my phone find the Chromecast when both are on Wi-Fi?
Most often they're not actually on the same network. Routers commonly broadcast 2.4 GHz and 5 GHz under different names, and a guest network isolates clients from each other by design. A VPN on the phone has the same effect. If they genuinely are on the same network name, suspect AP isolation at the router — the tell is that nothing on your network can see anything else, not just the Chromecast.
What is AP isolation and why does it break casting?
It's a router feature — also called client or station isolation — that stops devices on the same Wi-Fi network from talking to each other. It's correct on a public hotspot and wrong on a home network, and some ISP routers enable it by default. Casting depends on your phone finding the Chromecast on the local network, so with it on, everything has internet but nothing can see anything.
Why has the cast button disappeared from my apps?
On iPhone and iPad, that's usually Local Network permission. Without it the app genuinely cannot see devices on your Wi-Fi, so the button never appears. Check Settings → Privacy & Security → Local Network and enable the app you're casting from, not just Google Home. On Android, location services and an out-of-date Google Play services cause the same thing.
Should I factory reset my Chromecast?
Only after ruling out power, network and router causes — a reset on an underpowered device or one behind AP isolation will just fail to complete setup, and you'll have lost the configuration. It is genuinely the right fix for a Chromecast holding an old Wi-Fi password after a router or ISP change, which is a common reason one that worked for a year suddenly vanishes.
Sources and review notes
Checked on . Compiled by Glitchary from Google’s support documentation. App screens and menu names change between Google Home releases, and reset procedures differ by model — check Google’s current article for your device. Router settings such as AP isolation vary by manufacturer and are not covered by Google’s documentation; consult your router’s manual or ISP. Glitchary is independent of Google.