How to check your monitor is at 144 Hz
- Open this page on the 144 Hz monitor and keep the window there. With several screens, the reading is for the one the window is on.
- Wait two seconds without scrolling. The big number is the rate the browser draws at, and the box under it compares it with 144 Hz.
- Pass means the browser draws a new frame every 6.94 ms, as it does on a 144 Hz monitor. Below lists what to check on your system, and on Windows at a standard resolution it also works out how much video data your resolution needs at 144 Hz and which connections carry it. Browser limit means the browser itself is capped, by Safari’s 60 fps setting or by power saving, so the reading says nothing about the monitor yet.
- If your monitor is rated for a different rate, such as 165 Hz, pick it in the Rated refresh rate list: the verdict updates at once.
Why a 144 Hz monitor reads 60 or 120 Hz
60 Hz almost always means the refresh rate setting. In Windows 11, open Settings, System, Display, Advanced display, select the monitor and choose 144 Hz under Choose a refresh rate. Microsoft notes that the list only offers the rates your display supports, so a missing 144 Hz points at the connection, not the setting. With an NVIDIA card the same list is in the NVIDIA Control Panel under Display, Change resolution. On a Mac, open System Settings, Displays, select the monitor and use the Refresh rate menu. Safari also holds web pages near 60 fps by default, so test in Chrome or Firefox on a Mac.
120 Hz usually comes from the input. HDMI 1.4 runs at up to 340 MHz, and its specification lists 1080p at up to 120 Hz. With VESA’s tightest standard timing, 1080p at 144 Hz needs 333 MHz: it only just fits, and not every monitor offers it on that input. At 1440p, HDMI 1.4 can reach about 85 Hz even with the tightest timing, and many monitors stop at 60 or 75 Hz on it. The manual lists the top rate of each input: move the cable to DisplayPort or to an HDMI port rated for 144 Hz.
Reading the rest of the result
The chart should sit on the dashed line at 6.94 ms. Red bars are frames the browser missed because the computer was busy, not a fault of the monitor; a steady stream of them points to a heavy tab, an app or power saving. The motion test compares every refresh with 60 and 30 fps: at 144 Hz the top row looks clearly smoother than the 60 fps row. If all rows look alike, the display isn’t running above 60 Hz.
Faster screens have their own checks: the 240 Hz test compares 240 Hz with 120 and 60, and the frame skipping test catches an overclocked monitor that drops frames. On a phone, use the iPhone 120 Hz test or the Android refresh rate test, and for any other display the plain refresh rate test.
What 144 Hz needs from the connection
The video data a monitor needs grows with its resolution and refresh rate. This table works it out for 144 Hz with VESA’s reduced-blanking timing (CVT-RB2), the tightest standard timing, and compares it with what each connection carries after its line coding. It shows the oldest version that carries the signal uncompressed at 8 bits per colour, then at 10 bits (HDR).
The graphics card’s output and the monitor’s input must both support that version, with a cable certified for the speed: High Speed HDMI (10.2 Gbps), Premium High Speed (18 Gbps), Ultra High Speed (48 Gbps).
| Resolution at 144 Hz | Video data | DisplayPort | HDMI |
|---|---|---|---|
| 1080p1920 × 1080 | 8.0 Gbps10-bit: 10.0 Gbps | 1.2 or newer | 1.4 (only just) or newer10-bit: 2.0 or newer |
| 1440p2560 × 1440 | 14.1 Gbps10-bit: 17.6 Gbps | 1.2 or newer10-bit: 1.4 or newer | 2.0 (only just) or newer10-bit: 2.1 |
| Ultrawide 1440p3440 × 1440 | 18.8 Gbps10-bit: 23.5 Gbps | 1.4 or newer | 2.1 |
| 4K3840 × 2160 | 31.3 Gbps10-bit: 39.2 Gbps | 2.1 UHBR10 or newer, or 1.4 with DSC10-bit: 2.1 UHBR13.5 or newer, or 1.4 with DSC | 2.1 |
“Only just” means the signal fits with the standard timing but leaves under 5% to spare, so a monitor with looser timings of its own may stop short on that link: its manual has the final word. “With DSC” and “DSC only” refer to Display Stream Compression, which VESA added in DisplayPort 1.4 and describes as visually lossless; the monitor and graphics card both have to support it.
HDMI 2.1 ports run at 18 to 48 Gbps; the figures assume a full 48 Gbps port: check the monitor’s and card’s specs. Every HDMI 2.1 feature is optional, so a port sold as HDMI 2.1 may run no faster than HDMI 2.0.
| Connection | On the wire | Left for video |
|---|---|---|
| HDMI 1.4 | 10.2 Gbps | 8.16 Gbps |
| HDMI 2.0 | 18 Gbps | 14.4 Gbps |
| HDMI 2.1 | 48 Gbps | 42.67 Gbps |
| DisplayPort 1.2 | 21.6 Gbps | 17.28 Gbps |
| DisplayPort 1.4 | 32.4 Gbps | 25.92 Gbps |
| DisplayPort 2.1 (UHBR10) | 40 Gbps | 38.69 Gbps |
| DisplayPort 2.1 (UHBR13.5) | 54 Gbps | 52.22 Gbps |
| DisplayPort 2.1 (UHBR20) | 80 Gbps | 77.37 Gbps |
Sources: HDMI Licensing Administrator (HDMI 1.3 announcement: 340 MHz, 10.2 Gbps, the speed HDMI 1.4 keeps; HDMI 2.0: 18 Gbps; cable types: 10.2, 18 and 48 Gbps; HDMI 2.1 labelling: optional features) and VESA (DisplayPort 2.0 announcement: 25.92 Gbps of payload for DisplayPort 1.4, 77.37 Gbps for UHBR20). HDMI up to 2.0 and DisplayPort 1.x lose 20% to 8b/10b coding, HDMI 2.1’s fixed-rate link 11% (16b/18b over 3 or 4 lanes of 3 to 12 Gbps, Granite River Labs) and DisplayPort 2.1 about 3%.