Seek latency
Seek latency is how long playback takes to resume after a viewer jumps to a new point in the video. Long seek waits usually mean the CDN does not support byte-range requests well or the segments are long. It is also called jump latency.
Why it matters
Learners, sports fans and viewers rewatching key moments scrub constantly. Slow seeks make a product feel broken and discourage people from using chapters and replays. Tracking seek latency shows whether segment length, key frame spacing or CDN behavior is slowing every jump.
How it works
- The viewer drags the scrubber or taps a chapter to jump to a new time.
- The player finds the segment containing that time and requests it from the CDN.
- It downloads from the nearest key frame (a full picture frame) and decodes forward to the chosen point.
- The time from the jump to playback resuming is the seek latency for that jump.
Why does my video take so long to seek?
Seeking is slow when the player must download a lot of data before it can show the new point. Long segments, widely spaced key frames, distant CDN edges and players that request a high rendition after each jump all add delay. Shorter segments, key frames every two seconds and briefly dropping to a lower rendition after a seek help.
What is a good seek time?
A good seek time is under about one second, so a jump feels close to instant. Above two seconds, viewers notice and tend to scrub less. Learning platforms, where people jump around often, should aim for the low end and check seek latency by device and network.
Where it's used
Online learning platforms and corporate training teams care about seek latency because learners scrub back and forth constantly, and a two second wait on every jump makes a course feel broken.
Where it usually goes wrong, and how FastPix handles it
Seek delays rarely show up in startup or buffering reports, so teams miss them even though learners and replay viewers jump many times per view.
Jump latency in FastPix Video Data is total seek duration divided by the number of seeks in a view. FastPix also generates storyboard sprite sheets for scrubbing previews. That helps learners and fans land on the moment they want, so they keep using chapters and replays.
By the numbers
- Apple's HLS authoring specification recommends key frames every two seconds and segments of about 6 seconds. (HLS Authoring Specification for Apple Devices)
- Apple's HLS authoring specification requires I-frame playlists to support scrubbing and recommends dense I-frame renditions at one frame per second. (HLS Authoring Specification for Apple Devices)
