As discussed here, frame-by-frame video seeking is supported in several but not all browsers (test page).
If a user comes to my page, is there any reliable way to detect whether or not their browser supports frame-accurate seeking?
I ended up creating a small 1x4 video that shows a binary pattern each frame (0001 for frame 1, 0010 for frame two, etc), loading it in the background, and using <canvas>
element to read the data and check for accuracy.