Turn any TV into a giant countdown timer. Cast wirelessly with Chromecast or AirPlay, or plug in with a single HDMI cable — no app to install on the TV.
Go to castimer.com/timer and start a countdown. It is free and works instantly in the browser — no account required.
On the device connected to your TV, open the fullscreen display link and press "F" to enter fullscreen. This is the big-screen view your audience sees.
Mirror the display screen to the TV with Chromecast, AirPlay, or an HDMI cable. Your phone stays in control while the TV shows the timer.
The TV screen is black or shows the wrong tab
Make sure you are casting or mirroring the display screen, not the controller. Press "F" on the display screen to enter fullscreen.
The cast icon does not appear
Check that your phone or laptop and the TV are on the same Wi-Fi network, and that the Chromecast or AirPlay device is powered on.
Video is laggy or choppy
Close other browser tabs, move closer to the router, and prefer a 5 GHz Wi-Fi network. For critical events, an HDMI cable is the most reliable option.
The timer on TV stops updating
The display screen syncs in real time over the network. If the connection drops, refresh the display screen — the timer keeps running while you reconnect.
No. Castimer runs entirely in the browser. The TV simply mirrors the display screen from your phone or laptop, so nothing needs to be installed on the TV itself.
Yes. Casting is free and unlimited on every plan. You can display a fullscreen timer on any TV without paying anything.
Yes. That is the whole point of Castimer — control the timer from your phone while the TV shows the big display. Start, pause, add time, or send messages from anywhere in the room.
Any TV works: TVs with Chromecast built-in, TVs supporting AirPlay 2, or any TV or monitor with an HDMI input. See our Chromecast, AirPlay, and projector guides for details.
Free, instant, no installation required.