Technology/3 min exploration

The internet has an ocean floor

Trace the physical connections behind a world that feels wireless.

Experiment 0701 / YOUR INSTINCT

According to the ITU, what share of international data traffic travels through submarine cables?

Think about the main connections between networks worldwide. Estimate a share of international data traffic, not a share of internet users or devices.

YOUR ESTIMATE
50%INTERNATIONAL DATA TRAFFICUndersea cablesOther routes
The bar shows the traffic share. The network is an illustration, not a map of cable routes.
50%
None by cableAll by cable

A rough guess is enough.

The bigger picture International Telecommunication Union · 2025

What the numbers mean

The international backbone runs beneath the sea.

The International Telecommunication Union reported that more than 99% of international data traffic is carried by submarine telecommunications cables. A wireless connection near you can be one small part of a much longer physical journey.

Read the sources
01

A network has geography

ITU describes cables crossing oceans and networks connecting places across land. A message follows physical infrastructure, even when its first hop is wireless. Its route depends on the networks and servers involved. The global statistic cannot tell us where one particular message travelled, or whether it left its country at all. [1]

02

Many routes make a stronger connection

The International Cable Protection Committee explains why networks need backup routes. If a cable fails, operators can redirect traffic where another connection has enough capacity. They also monitor cable performance. A reliable service depends on those alternatives and on maintenance; a single cable does not have to carry every journey. [2]

03

A digital world still needs physical maintenance

Natural hazards, fishing and other human activities can damage cables. Repairs need specialised equipment, crews and permission to reach the affected area. The committee explains how route planning and repair access affect reliability. The connections behind a video call or a cloud service still depend on people working in the physical world. [2]

Sources & method

How we worked it out.

International Telecommunication Union · 2025

ITU's Global Connectivity Report 2025 states more than 99% of international data flows. The visual uses 99 as the stated lower bound; the exact share is not supplied. This does not describe all internet traffic, every cross-border route, or the fraction of people using satellites. Routes shown are illustrative.

  1. 01International Telecommunication UnionGlobal Connectivity Report 2025: international data flows (opens in a new tab)
  2. 02International Cable Protection CommitteeFrequently asked questions: resilience and cable routes (opens in a new tab)