Measured ICMP round-trip times from Seattle, USA to Tokyo, Japan: average 85 ms, min, max, jitter, and packet loss for this North America to Asia route.

🇺🇸 Seattle, USA (SEA) → 🇯🇵 Tokyo, Japan (TYO)

Measurement round: 2026-08-16T04:07:28Z.

In the 2026-08-16T04:07:28Z measurement round, ICMP echo requests from Seattle, USA to Tokyo, Japan produced an average round-trip time of 85 ms, with a minimum of 81.03 ms and a maximum of 97.43 ms. All 50 samples were received, and jitter measured 2.59 ms.

The average sits roughly 13% above the estimated fiber floor for the 7,715 km geodesic distance, leaving only a small overhead for a long trans-Pacific path. The 3.15 ms standard deviation keeps the round-trip times tightly grouped, making this a stable low-latency route to East Asia.

The route ranked fifth among the network's 19 measured outbound routes in this round. Its standard deviation is about 3.7% of the average RTT, close to the network's median ratio of 3.3%, and packet loss was zero, so the path is both quick and dependable relative to the measured set.

Latency Summary

Metric	Value
RTT	85 ms
Jitter	2.59 ms
Packet Loss	0%
Standard Fiber Floor	75.55 ms
Fiber Efficiency	88.9%
Latency Tier	Good
Source Region	North America
Destination Region	Asia Pacific

Ping Measurement Series

The chart below renders the 50-sample ICMP echo measurement round for this route; an accessible table of every sample is included with the chart.

Ping series: SEA → TYO

50 ICMP echo samples at 100 ms intervals · round 2026-08-16T04:07:28Z · avg 85.0 ± 0.45 ms (SE)

Sample distribution: box = interquartile range (82.7–86.2 ms), median 84.5 ms · whiskers = min–max · diamond = round average · each dot is one measured sample.

How to read this chart

The shaded band spans the measured minimum to maximum RTT of all samples collected up to that point, and the thin line traces the running average. The final position therefore matches the round statistics exactly — the band only widens when a new extreme sample arrives.

The dashed line is the round average, and the shaded band at the bottom is the theoretical fiber-optic floor (75.5 ms) for this route.

Full 50-sample dataset

Seq	Offset (ms)	RTT (ms)
1	0	86.50
2	100	90.87
3	200	84.46
4	300	83.76
5	400	81.68
6	500	81.03
7	600	81.32
8	700	82.16
9	800	82.38
10	900	89.29
11	1000	87.63
12	1100	84.64
13	1200	83.05
14	1300	81.71
15	1400	83.88
16	1500	81.71
17	1600	81.45
18	1700	86.68
19	1800	86.18
20	1900	85.06
21	2000	85.13
22	2100	83.17
23	2200	82.08
24	2300	81.10
25	2400	86.66
26	2500	86.16
27	2600	97.43
28	2700	89.52
29	2800	89.74
30	2900	84.42
31	3000	89.90
32	3100	85.64
33	3200	84.36
34	3300	82.66
35	3400	85.67
36	3500	82.84
37	3600	86.14
38	3700	84.34
39	3800	89.15
40	3900	85.45
41	4000	84.67
42	4100	84.86
43	4200	82.33
44	4300	82.91
45	4400	84.58
46	4500	82.80
47	4600	82.76
48	4700	82.55
49	4800	89.62
50	4900	85.92

Download This Route's Data

This route's measurement round is published as open data (CC BY 4.0) in CSV, JSON, and YAML. See About This Measurement for citation guidance.

Download this dataset

Per-route ICMP ping series, released under CC BY 4.0. Uncompressed plain text — no decompression step needed.

CSV JSON YAML Full dataset

Theoretical Fiber Latency

The public physical reference uses the GeoNames city centres for Seattle (47.60621, -122.33207) and Tokyo (35.68950, 139.69171). It does not disclose either facility address.

Physical Reference	Value
WGS-84 geodesic distance	7,715.2 km
Vacuum RTT floor	51.47 ms
Standard fiber RTT floor ( $n_g=1.4679$ )	75.55 ms
Low-latency fiber material floor	75.25 ms
Engineering floor (5% path allowance)	79.34 ms
Research 1.33× mapped-fiber reference	100.49 ms
Estimated unamplified path loss	1620.2 dB
Transparent optical spans / inline amplifiers	102 / 101
Published RTT inflation over fiber floor	1.13×

Attenuation is used to estimate the number of 80 km optical spans; it does not directly slow light. See the full theoretical fiber latency, GeoNames, attenuation, and amplifier methodology.

Stability & Trend

The current measurement round (2026-08-16T04:07:28Z) collected 50 ICMP echo samples on this route. Distribution statistics from that round:

Round Statistic	Value
Minimum RTT	81.03 ms
Average RTT	85 ms
Maximum RTT	97.43 ms
Standard deviation	3.15 ms
Stdev / average	3.7%

RTT trend

Estimated route stability across the selected time window.

Average: 85.1 ms
Minimum: 84.3 ms
Maximum: 85.9 ms
Average loss: 0.03%

Route Context

Departure PoP: Seattle (SEA)
Destination PoP: Tokyo (TYO)
Region overview: North America → Asia Pacific
Corridor overview: North America to Asia Pacific
Full global matrix: Backbone Latency Matrix
Physical methodology: Theoretical Fiber Latency

Reverse direction

Tokyo to Seattle latency and RTT — 84.8 ms

Fastest routes departing Seattle (SEA)

Seattle to Los Angeles latency and RTT — 25.9 ms
Seattle to New York latency and RTT — 59.5 ms
Seattle to Ashburn latency and RTT — 61.5 ms
Seattle to Miami latency and RTT — 81.7 ms
Seattle to Taipei latency and RTT — 114.7 ms

Fastest routes arriving at Tokyo (TYO)

Taipei to Tokyo latency and RTT — 31.9 ms
Hong Kong to Tokyo latency and RTT — 44.9 ms
Singapore to Tokyo latency and RTT — 68.9 ms
Los Angeles to Tokyo latency and RTT — 101.2 ms
Sydney to Tokyo latency and RTT — 101.3 ms

Same corridor (North America → Asia Pacific)

Seattle to Hong Kong latency and RTT — 130.4 ms
Los Angeles to Taipei latency and RTT — 132.9 ms
Los Angeles to Sydney latency and RTT — 137.6 ms

About This Measurement

Published RTT reflects best-case backbone path behavior measured with ICMP echo probes between PoPs. End-user latency also depends on local access networks, congestion, routing policy, and traffic engineering. None of these values is an SLA.

The measurement round behind this page is published as open data under CC BY 4.0 in the Hats Network latency dataset. Per-pair files are available at /opendata/latency/latest/pairs/sea-tyo.pings.{csv,json,yaml}. When citing, include the route, the measurement round timestamp, and the dataset version — for example: "Hats Network latency dataset, Seattle → Tokyo round 2026-08-16T04:07:28Z, CC BY 4.0".

Data auto-generated on August 16, 2026. Explore the full interactive latency matrix or browse more city-pair routes.

Seattle, USA → Tokyo, Japan RTT