HDMI DISPLAY GUIDE
Poker Timer on a TV over HDMI: Extend the Display
An HDMI cable is the most reliable way to put a poker clock on a TV, because it never touches the network. The choice that matters is whether you duplicate or extend the display.
Updated · 2026-09-14
1. Duplicate vs extend, and why it matters
Every laptop can send its picture to a TV over HDMI in one of two modes. Duplicate, sometimes called mirror, shows the same image on both screens. Extend treats the TV as extra desktop space next to the laptop.
Duplicate is the fastest to set up and works well when you are happy for the laptop and TV to show exactly the same thing. Extend is worth the extra step when you want a clean full-screen clock on the TV while your laptop screen stays available for other windows.
2. Why extend helps a home game
With extend, the TV can show only the tournament clock, full screen, while your laptop shows your desktop. That keeps chip-count spreadsheets, structure notes, or a payout page on the laptop without those windows appearing on the shared screen.
- TV: a clean full-screen clock the whole room watches
- Laptop: free for notes, chip counts, or the payout calculator
- No network involved, so nothing to drop mid-level
3. Set it up on Windows
Plug in the HDMI cable, switch the TV to that HDMI input, then set the display mode.
- Press Win+P and choose Duplicate or Extend
- For Extend, open the free WTGB timer at / and drag its window onto the TV display
- Press F11, or the timer full-screen button, so the clock fills the TV
- Leave the browser window focused so keyboard controls reach the timer
4. Set it up on Mac
Connect with a USB-C or HDMI adapter, then open System Settings and then Displays. Choose Mirror for duplicate, or arrange the displays for extend, drag the timer window onto the TV, and use the timer full-screen button.
5. Where the controls live
The free web timer is a single page, so its Start, pause, previous, next, reset, sound, and edit controls live in that one window. In duplicate mode both screens show those controls; in extend mode they sit wherever you place the timer window. Many hosts run the whole night from the keyboard while watching the TV.
If you want the player-facing clock and your controls on truly separate screens, with the controls in your hand and a clean clock on the TV, that is what the WTGB iOS app does with AirPlay. See /guides/how-to-airplay-poker-timer-from-ipad and the trade-offs in /guides/poker-timer-app-vs-browser.
6. Test before the first hand
A short test catches the problems that actually disrupt a game night.
- Read the current blinds and remaining time from the farthest seat
- Confirm the next level is visible so the table can prepare
- Press Start once and check the one-minute warning and level-change beep are audible
- Keep the laptop awake and on power, and avoid refreshing the timer tab
- For wireless alternatives, compare /guides/chromecast-poker-blinds-timer and /guides/how-to-show-poker-timer-on-tv
PUT IT INTO PRACTICE
Turn the guide into tournament settings
Open the related WTGB toolFAQ
Common questions
What is the difference between duplicate and extend?
Duplicate shows the same image on the laptop and the TV. Extend treats the TV as extra space, so you can put a full-screen clock on the TV while your laptop screen stays free for other windows.
Can I keep the controls on my laptop and the clock on the TV?
With a single browser page the controls sit in the timer window wherever you place it, and many hosts run it from the keyboard. For controls on one device and a clean clock on another, use the WTGB iOS app with AirPlay. See /guides/how-to-airplay-poker-timer-from-ipad.
Do I need internet for an HDMI display?
HDMI itself uses no network. You still need a connection to load the timer page once, after which it runs in the browser, but it is not an installable offline app, so keep the tab open. See /guides/offline-poker-blinds-timer.
How do I switch to extend on Windows and Mac?
On Windows press Win+P and choose Extend. On Mac open System Settings and then Displays and arrange the screens instead of mirroring, then drag the timer window onto the TV and go full screen.
HDMI or Chromecast for a home game?
HDMI is the most reliable because it avoids the network entirely. Chromecast is more convenient and wire-free but depends on Wi-Fi. See /guides/chromecast-poker-blinds-timer to compare.