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:

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

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.

:
All Devices
MobileDesktop
<100ms
100–150ms
150–200ms
200–250ms
>250ms
Rank
Country
p50
1.
Netherlands
63ms
2.
Norway
75ms
3.
Sweden
77ms
4.
Denmark
79ms
5.
Switzerland
82ms
6.
Belgium
83ms
7.
United Kingdom
84ms
8.
Taiwan
84ms
9.
Germany
87ms
10.
Czechia
87ms
...
...
...
61.
Uzbekistan
210ms
62.
Kazakhstan
213ms
63.
Egypt
214ms
64.
Venezuela
231ms
65.
South Africa
242ms
66.
Kenya
255ms
67.
Sri Lanka
264ms
68.
Iran
282ms
69.
Pakistan
287ms
70.
Nigeria
339ms

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:

:
All Devices
MobileDesktop
Shopping
81ms
95ms
115ms
145ms
190ms
37ms
128ms
726ms
5,022
Beauty & Fitness
82ms
96ms
116ms
141ms
188ms
51ms
127ms
386ms
1,161
Food & Drink
84ms
99ms
116ms
147ms
216ms
39ms
132ms
436ms
1,076
Autos & Vehicles
88ms
102ms
120ms
156ms
201ms
45ms
136ms
512ms
1,208
Travel & Transportation
89ms
107ms
126ms
162ms
215ms
51ms
143ms
819ms
1,358
Business & Industrial
83ms
100ms
129ms
171ms
237ms
33ms
147ms
1108ms
2,853
Sports
89ms
107ms
131ms
179ms
245ms
48ms
151ms
614ms
2,260
Computers & Electronics
82ms
104ms
135ms
180ms
237ms
27ms
150ms
1025ms
3,053
News
89ms
107ms
135ms
180ms
243ms
42ms
152ms
778ms
7,516
Games
84ms
102ms
136ms
183ms
250ms
39ms
152ms
658ms
2,982
Finance
84ms
102ms
137ms
181ms
241ms
40ms
150ms
556ms
2,405
All ☼
87ms
106ms
138ms
193ms
259ms
21ms
158ms
1766ms
49,801
Jobs & Education
75ms
96ms
138ms
192ms
248ms
36ms
151ms
576ms
4,274
Law & Government
85ms
105ms
141ms
188ms
233ms
36ms
152ms
546ms
2,113
Internet & Telecom
88ms
111ms
144ms
198ms
255ms
39ms
163ms
1766ms
3,248
Books & Literature
93ms
113ms
147ms
198ms
250ms
46ms
160ms
555ms
1,417
Online Communities
87ms
111ms
148ms
211ms
269ms
39ms
166ms
713ms
2,812
Arts & Entertainment
93ms
115ms
154ms
216ms
275ms
39ms
172ms
731ms
10,144
Adult Content
98ms
123ms
171ms
240ms
298ms
21ms
188ms
972ms
6,479

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.