Support
Everything the device knows about itself is on its own status page at
http://castmute.local, reachable from any phone or computer on the same Wi-Fi.
Start there.
What the light means
| Green | Watching. Everything is normal. |
| Green flash | Muting an ad break right now. |
| Purple | No Cast device found. |
| Blue | Joining Wi-Fi. |
| Red | Cannot join Wi-Fi — usually a wrong password. |
| Amber | Waiting to be set up. |
The light is purple
It joined your Wi-Fi but found no televisions. Check the TV is switched on, that it is a Chromecast or has Chromecast built in, and that it is on the same network as CastMute — a guest network or a separate band counts as a different network on many routers.
Some mesh routers block the discovery messages CastMute uses. If the TV is definitely there, open the status page and add its IP address by hand under Add a TV by hand. You will find the address in your router's device list.
The light is red
Wrong Wi-Fi password, nine times in ten. Hold a paperclip in the reset pinhole for five seconds to start setup again. It also goes red if the router is rebooting, in which case it recovers on its own.
I can't open castmute.local
Some Android phones and a few routers do not resolve .local names. Find the
device's IP address in your router's device list and type that into the browser instead.
If you have two CastMutes on one network they will both answer to
castmute.local and only one of them wins. Use IP addresses to tell them apart.
One box already covers several televisions, so a second one is rarely needed.
Ads aren't being muted
Check the light is green and the TV appears on the status page. Then check the service: CastMute recognises ad breaks on Disney+, Prime Video, Hulu and YouTube. Where a service stitches its ads into the video stream, nothing outside that app can tell an ad from the programme, and CastMute cannot help.
It also only works when you cast to the TV from a phone, tablet or laptop. An app you open with the TV's own remote is invisible to it.
It muted my programme, or didn't unmute
Worth reporting — that is a bug, not a setting. Send the details in the last section below, along with the service and roughly when it happened.
If you mute the TV yourself, CastMute notices and leaves your mute alone rather than fighting you for the volume.
Moving it to a different Wi-Fi network
Open the status page and use Change Wi-Fi network at the bottom. The device forgets the old network and restarts into setup mode with an amber light.
Resetting it
There is a small hole in the lid. With the device already plugged in, push a paperclip in and hold for five seconds — the light blips while it counts, then flashes three times and restarts into setup mode.
Hold it while it is already running, not while plugging it in. Pressing that button as power arrives puts the chip into a firmware loading mode, where it looks dead and does nothing. Unplug it and plug it back in without pressing anything and it recovers.
Updates
Automatic. It checks twice a day and installs anything newer. If an update fails to start up properly the device falls back to the previous version by itself, so a bad release cannot leave you with a dead box. The version it is running is shown on the status page.
Power
Any USB charger. It draws well under a watt — leave it plugged in permanently. There is no battery and no power switch.
Reporting a problem
Open http://castmute.local, scroll to Device, and copy all of
it into an email. Those numbers answer most of what I would otherwise have to ask you:
- Firmware — the version, and which of the two slots it booted from
- Free memory, Largest block, Lowest ever — whether it is running out of room, which the first two numbers alone can hide
- Reconnects, Frames skipped — how stable its connection to the TVs is
- Wi-Fi signal, Worst seen — nearly every odd symptom traces back to these two
Then tell me what you expected and what happened instead, which service, and which TV.