Firefox is hopelessly broken (timers/vsync/etc) -- DO NOT USE! VSYNC in Firefox under Windows is broken -- Details
Edge and IE do not support high Hz displays -- Details
Web browser "VSYNC synchronization" tester vsynctester.com - A novel way to EASILY verify web browser VSYNC synchronization, display Hz, and input lag!
VSYNC indicator, rgb (0-255)
Performance graph, scale ms (1-100)
frame VSYNC offset (blue) locked
'late' / vsync offset per rAF time (purple)
inter-frame (green/red) right scale
render time (brown)
'spin-wait' (gray)
Use rAF time arg as frame time
Custom Hz (1-500), skew ms (0-25)
Precise timing via spin wait up to ms (1-9)
Maximum setTimeout() ms of ms (9-50)
Background images MP (1-99) Preview
Use up to (1-20) images
Stress
Scroll pixels/frame (1-50)
Mouse input lag indicator frames (0-9)
Odd Even frame pre-delay to ms (0-20)
Odd Even frame post-delay to ms (0-20)
Tear helper/bar pixels (1-20)
Drop 1 in every frames (1-200)
Frames indicator pixels (5-33)