Screen Refresh Rate & Hz Test
Understanding Hz vs. FPS
Refresh rate (Hz) is the hardware speed of your monitor. FPS (Frames Per Second) is how fast your browser renders images. This tool locks your browser's FPS to your display's V-Sync, giving you a precise measurement of your active screen Hz.
Stuck at 60Hz? How to Unlock High Refresh Rate
Windows defaults to 60Hz. Go to Settings > System > Display > Advanced display. Under "Refresh rate," select the highest available Hz (e.g., 144Hz or 240Hz).
Still stuck? Read our deep-dive technical audit on fixing Windows 11 refresh rate limits →
Open System Settings > Displays. Click the "Refresh rate" dropdown and choose your display's maximum supported rate (e.g., 120Hz ProMotion).
Using an external monitor? Learn how to bypass WindowServer limits and force 120Hz/144Hz on MacBooks →
For iPhone, go to Settings > Accessibility > Motion, and ensure "Limit Frame Rate" is OFF. For Android, check Settings > Display > Screen refresh rate.
Old cables restrict refresh rates. Ensure you use a DisplayPort (DP) cable or a certified HDMI 2.1 cable. Also, check if your browser's "Hardware Acceleration" is enabled.
Note: Browser limitations can cap your FPS. Learn how to properly configure browser hardware acceleration →
Frequently Asked Questions
Does HDMI support 144Hz?
HDMI 2.0 supports 144Hz at 1080p, and HDMI 2.1 extends support to 144Hz at 4K. Older HDMI 1.4 cables are often capped at 60Hz. For consistent 144Hz+ performance on a PC, a DisplayPort 1.2 connection or newer is recommended.
How to enable 120Hz on iPhone or Android?
iPhone: Open Settings > Accessibility > Motion, then turn "Limit Frame Rate" OFF. Android: Open Settings > Display > Screen refresh rate, and choose 120Hz (or highest available). Note: Battery saver modes will often force your screen back to 60Hz.
Do G-Sync or FreeSync affect this test?
Adaptive sync technologies adjust your screen's refresh rate dynamically to match GPU output. However, during this browser-based test, your monitor will operate at its peak Hz capability, so you will measure the maximum refresh rate, not a fluctuating one.
How does this test work (FPS vs Hz)?
This tool uses your browser's hardware-accelerated rendering to measure FPS. Because web browsers automatically synchronize their frame rate (V-Sync) with your monitor's physical refresh rate, this FPS measurement accurately reflects your active screen Hz.
Why does Windows or macOS say 144Hz, but this test still looks stuck at 60Hz?
That usually means the bottleneck is somewhere between the OS setting, the cable, and the browser render path. Start with our Windows 11 144Hz troubleshooting guide, our MacBook external monitor 60Hz guide, and our HDMI vs. DisplayPort bandwidth breakdown.
Related Refresh Rate Diagnostics
Fix a monitor that is stuck at 60Hz on Windows 11
Follow our Windows 11 deep-dive to check cable bandwidth, GPU output path, and browser throttling before you blame the panel.
Fix a MacBook external display that will not switch to 120Hz/144Hz
Use our MacBook high-refresh guide if your USB-C or Thunderbolt setup still reports 60Hz.
Compare cable limits: HDMI vs DisplayPort vs USB-C
Read HDMI vs DisplayPort at 144Hz and USB-C to 144Hz monitor support if the advertised refresh rate disappears at higher resolutions.
Check frame pacing and skipped frames after changing refresh rate
After you confirm Hz, run the Frame Rate Test to catch browser stutter, skipped frames, and unstable pacing.
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