Netflix ended 2018 with more than 139 million paid subscribers, adding 8.8 million users in the three months to December 31.
The streaming giant said growth reflected the success of its original programs, such as the Bird Box and Rome.
Netflix's original material now represents the "vast majority" of its most popular shows, executives said.
Viewers in the US also spend about 10 percent of their time on Netflix, they said.
The numbers followed the release of the company's quarterly earnings report on Thursday.
They offered investors a rare glimpse of audience standards as the company seeks to explain how its massive spending on content – largely debt-financed – is paying off.
Analysts estimate that Netflix has spent more than $ 13 billion in movies and shows this year.
Netflix said its spending is likely to rise.
"Our multiyear plan is to continue to grow our content significantly while increasing our revenue quickly to expand our operating margins," Netflix said in a shareholder statement linked to the earnings report.
"Our growth is based on how good our experience is," he said.
Shares, which rose sharply in recent weeks, fell more than 3 percent on the trading floor after hours after fourth-quarter revenue fell short of analysts' expectations.
The company reported quarterly revenue of $ 4.2 billion, up 27 percent from the same period in 2017.
However, rising prices in the US and some Latin American and Caribbean countries announced this week have the potential to add about $ 1 billion in revenue.
The company said it will also seek to adjust prices elsewhere as the currencies fluctuate, but warned that the increases may lag behind changes in the exchange rate, causing revenue problems.
George Salmon, an analyst at Hargreaves Lansdown, said he expected Netflix subscribers to bring the higher rates.
The increase of 8.8 million paid subscribers – mostly from abroad – grew by 6% over the previous quarter.
He added, "The concern, of course, is that international brutes like Disney and Amazon are not going to fall out without fighting, and both have the financial power to fight back quite a bit.
Dave Lee, BBC technology reporter North America, San Francisco
In their letter to shareholders, there is a clear passage about where Netflix's real competition is.
The company said it faces more competition from people watching video clips of the Fortnite video game about those watching rival HBO.
"When YouTube fell into the world for a few minutes in October, our viewing and subscriptions increased during that time," he added.
It's what makes forecasting the future of Netflix so interesting – they are not so much in the entertainment business but in the business world.
You, the consumer, have more than ever to look at, or interact with, and the competition for Netflix will only get tougher in 2019.
In the letter, Netflix took the time to increase its success – the Bird Box, which estimates it will be assisted by 80 million households within four weeks of its launch, and a Spanish-language exclusivity, Elite, which attracted more than 20 millions.
All of this is positive news, but we'll know more about the company's health in three months, when we'll find out if consumers have issues with Netflix's recent price increase in the US and some other countries.
As for today's profits, they are quite common: with the disappointing Wall Street company in some measures (revenue), but surpassing the expectation in others (subscriber growth). As I write this, stocks are down – but I expect the price to recover quickly.