ntpstats

Network time analysis, 2026 edition

Load clock-offset logs from ntpd 4.2.8, NTPsec or chrony, a CSV from ntpstats monitor, or generate a simulated NTP exchange with known ground truth.

  • Offset — time series with detrending, outlier rejection, Kalman / RTS / min-delay overlays. Drag to zoom.
  • Stability — ADEV, overlapping ADEV, MDEV, TDEV, Hadamard and MTIE with χ² confidence bands and automatic noise identification.
  • Network — delay floor, offset-vs-delay wedge, asymmetry indicator and floor packet percentage (G.8260 style).

Histogram of the offset (after the selected detrending) with a Gaussian of equal mean and standard deviation. Heavy tails indicate queueing spikes or path changes.

Offset vs. queueing delay (wedge)

Round-trip delay

Floor packet percentage

Simulate NTP exchanges

Free-running oscillator (frequency offset, drift, white/random-walk FM) measured through an asymmetric queueing network. The dataset carries a true_offset column so filters can be scored against ground truth.

Live measurement

SNTP queries from this machine (random transmit timestamp, KoD aware). Please poll public servers no faster than every 64 s.