Three in four people are online. The last quarter is the hard part.

In 2005, about 16 percent of the world's people used the internet. The share crossed half in 2019, jumped six points in the pandemic year of 2020 as work and school moved online, and reached roughly 74 percent in 2025. On the chart, that is a textbook adoption S-curve — and the world has now climbed onto its upper shoulder, where the slope begins to fade.

You can see the ceiling in the countries that arrived first. High-income countries as a group sit at about 94 percent — South Korea at 98, the United States at 95 — figures that, once you subtract small children and the resolutely offline, amount to everyone. The rich world's curves have been effectively flat for years. There is nobody easy left to connect.

The remaining quarter is not a thinner version of the connected three-quarters; it is a different population. Low-income countries average about 23 percent online — roughly where the rich world stood two decades ago. In all, more than two billion people remain offline, concentrated where electricity, network coverage and incomes are weakest. The global curve is behaving accordingly: the yearly gain has fallen from six percentage points in 2020 to about two now.

The internet has run out of easy people to connect.

That is what saturation looks like from the inside. Most of the world came online within a single generation because networks reached people who could afford to join them the moment the wire, or the signal, arrived. The last quarter requires the opposite: grids, towers and prices reaching people the market has so far skipped. S-curves flatten for a reason — the end of an adoption story is always slower, and more expensive, than its middle.