How NTP Synchronizes Clocks

NTP estimates time through repeated timestamp exchange over an imperfect network. Watch a client gradually discipline its clock against a reference server.

Ready Press Play to start the NTP synchronization loop.
Round
—
Raw offset
—
single-sample estimate
Filtered offset
—
smoothed over rounds
Round-trip delay
—
network latency
Correction applied
—
cumulative adjustment
Remaining error
—
client − server
Offset estimate over sync rounds
Raw measurement Filtered estimate True remaining error ── zero line
Speed 1.0×
Presets:
Key idea: NTP does not assume a perfect network. Each exchange is noisy, so the client filters measurements over time and steers its clock gradually — favoring robust, practical synchronization across ordinary networks.