Round-Trip Time

Deep dive into network latency on the web: an interactive report based on Round-Trip Time (RTT) data from Chrome UX Report (CrUX).

Overview

This is an interactive report to explore network latency on the web. It addresses questions such as: What is the current health of the network? How does it vary by country and website categories? It uses Round-Trip Time (RTT) data from Chrome UX Report (CrUX).

RTT shows the time it takes for a request to go from a client to the server and back (round-trip). In CrUX, it is estimated on the initial page load navigation using navigator.connection.rtt and measured in milliseconds. CrUX provides 75th percentile (p75) aggregated for all domain visits during the past 28 days.

RTT is a diagnostic metric that helps you to understand your audience network connection. Instead of relying on 2G, 3G, or 4G labels (which are also based on RTT), it provides better visibility to your visitors' connection. For example, if your site's average RTT is slow, performance metrics like TTFB or LCP are also likely to be impacted. Consider loading some parts of your site conditionally (learn more). But if RTT is fast and you still have slow metrics, you need to optimize your site. We tried to define fast & slow buckets on the map below. To measure your site's performance, use our free Site Speed Test.

Methodology: we took RTT data for the top 50,000 domains aggregated during November 24 (excluding empty values, which resulted in 49,801). Here are the median (p50) values by device type:

Mobile
151ms
Desktop
96ms
All Devices
138ms

Usually, 70% of a website's traffic is mobile, which explains why the All Devices value is closer to Mobile than Desktop. The table below provides a detailed breakdown of the RTT distribution with percentiles and statistics:

Mobile
100ms
116ms
151ms
207ms
267ms
34ms
170ms
1773ms
48,876
Desktop
65ms
75ms
96ms
126ms
171ms
12ms
109ms
934ms
41,082
All Devices
87ms
106ms
138ms
193ms
259ms
21ms
158ms
1766ms
49,801

Geography

Let's explore RTT by country. The regional difference is clear and reflects countries' GDP and the location of data centers. Australia and New Zealand famously experience higher RTT due to speed of light limitations, as data centers are primarily located in the US and Europe. We computed regional RTT using top-level domains (TLDs). For example, .nl represents the Netherlands, and .ca is Canada.

The map below displays the median RTT (p50). And the table on the right lists the top 10 fastest and slowest countries. You can interact with the map and use the device switch to change aggregation.

<100ms
100–150ms
150–200ms
200–250ms
>250ms
Rank
Country
p50
1.
Taiwan
51ms
2.
Netherlands
53ms
3.
Switzerland
57ms
4.
Sweden
58ms
5.
Norway
61ms
6.
Japan
66ms
7.
Denmark
66ms
8.
Germany
67ms
9.
Czechia
67ms
10.
Belgium
68ms
...
...
...
61.
South Africa
165ms
62.
Egypt
167ms
63.
Kazakhstan
169ms
64.
Saudi Arabia
180ms
65.
Venezuela
184ms
66.
Sri Lanka
207ms
67.
Kenya
219ms
68.
Pakistan
239ms
69.
Iran
244ms
70.
Nigeria
338ms

Categories

The network latency varies up to 50% by website category. Sectors like E-commerce or Auto-industry tend to invest more in web performance, resulting in lower RTT. In contrast, categories like Entertainment or Adult content, are much slower. To classify websites, we used Chrome's topic classifier (chrome://topics-internals/). Below is an interactive table to explore the network latency across different clusters of the web:

Travel & Transportation
63ms
72ms
87ms
111ms
138ms
30ms
97ms
808ms
1,194
Sports
64ms
72ms
84ms
111ms
149ms
36ms
99ms
388ms
1,828
Shopping
63ms
71ms
83ms
105ms
133ms
31ms
93ms
438ms
4,667
Online Communities
63ms
77ms
101ms
135ms
178ms
30ms
114ms
582ms
2,231
News
64ms
74ms
90ms
118ms
162ms
30ms
104ms
409ms
6,090
Law & Government
68ms
81ms
109ms
152ms
198ms
30ms
123ms
437ms
2,025
Jobs & Education
66ms
79ms
109ms
150ms
197ms
33ms
122ms
537ms
3,970
Internet & Telecom
67ms
81ms
105ms
138ms
180ms
36ms
117ms
795ms
2,644
Games
62ms
74ms
90ms
114ms
141ms
34ms
99ms
436ms
2,225
Food & Drink
61ms
69ms
79ms
99ms
129ms
33ms
89ms
274ms
932
Finance
66ms
77ms
96ms
128ms
177ms
32ms
111ms
463ms
2,104
Computers & Electronics
65ms
78ms
99ms
127ms
162ms
17ms
109ms
463ms
2,669
Business & Industrial
64ms
74ms
93ms
120ms
166ms
32ms
107ms
934ms
2,504
Books & Literature
64ms
76ms
100ms
127ms
157ms
40ms
107ms
342ms
1,262
Beauty & Fitness
63ms
71ms
82ms
104ms
127ms
38ms
92ms
295ms
1,087
Autos & Vehicles
65ms
72ms
86ms
109ms
136ms
36ms
95ms
323ms
1,068
Arts & Entertainment
66ms
79ms
104ms
135ms
186ms
33ms
116ms
582ms
7,889
All ☼
65ms
75ms
96ms
126ms
171ms
12ms
109ms
934ms
41,082
Adult Content
67ms
82ms
106ms
133ms
172ms
12ms
115ms
458ms
4,537

Next: This is the first iteration of the report. We plan to expand its functionality once more RTT data is available in CrUX. Feel free to contact us via Email or Twitter and suggest your ideas and improvements.