Time to first frame (TTFF)
Time to first frame (TTFF) is the time it takes from a playback request until the first video frame appears on the viewer's screen. TTFF is a precise, technical form of startup time measured inside the player. It is usually recorded in milliseconds and tracked both as an average and at slower percentiles, such as the 95th percentile.
Why it matters
TTFF turns a vague complaint, that the video feels slow, into a number engineers can chase. Saving even a few hundred milliseconds matters most in short video feeds and live streams, where viewers decide in seconds whether to stay. Tracking slow percentiles shows how many viewers get a bad first impression.
How it works
- The clock starts when the player receives a playback request, such as a tap on play or an autoplay trigger.
- The player loads the manifest, picks a quality level and requests the first media segment.
- Any DRM license is fetched, and the first segment is downloaded and passed to the decoder.
- The clock stops when the first frame appears on screen, and the time is reported in milliseconds.
What is a good time to first frame?
A good time to first frame is about 1 second or less, with 2 seconds as a practical upper limit, since research shows viewers start abandoning after about 2 seconds. Short video apps often preload the next clip so TTFF feels instant. Look at the 95th percentile as well as the average. An average of 800 milliseconds can hide many viewers who wait 4 seconds or more.
How do you reduce time to first frame?
You reduce TTFF by cutting what must load before the first frame. Preload the player and manifest before the viewer taps play. Start on a lower quality level, use short first segments and keep the manifest and first segments cached close to viewers on the CDN. Request DRM licenses early, and test on slow real devices, not only fast laptops.
Where it's used
Engineers at OTT services, short video apps and live sports streamers use TTFF to find where playback delays come from, then test fixes such as preloading, shorter segments or a different CDN.
Where it usually goes wrong, and how FastPix handles it
Many teams report only an average startup figure. Averages hide the slow tail, and they do not show which device, network or region is causing the delay.
Time to first frame shows up in FastPix Video Data as video startup time for each view, turned into a startup score and broken down by device, browser, country, ISP and CDN, so you see which viewers wait too long and fix the cause where it keeps the most people watching.
