Asians are among the heaviest users of smartphones in the world. Partially this is because many countries like South Korea and Singapore have fast, modern connectivity, and partially this is because of the popularity of WeChat in China and Line in Southeast Asia, Korea and Taiwan.

But connectivity speed and security is certainly not uniform across Asia. Recently OpenSignal a company which tracks cellular and wifi speeds around the world, published a report of mobile connectivity across Asia. The results are fascinating.

When it comes to 4G download speed, OpenSignal identified three distinct groupings of cities. Seoul and Singapore are in a class of their own, offering average download speeds greater than 45 Mbps. That makes them not just the fastest cities in East Asia, but among the fastest cities in the world. And it makes them great cities to do a lot with your smartphone.

Below Seoul and Singapore, is a group of cities with impressive 4G download speeds over 25 Mbps, indicative of powerful LTE networks. While we would expect Taipei and Tokyo to be LTE powerhouses, given their early adoption of 4G, Yangon and Ho Chi Minh City are holding their own. Both Vietnam and Myanmar only launched commercial 4G services within the last two years, which perhaps explains why they’re delivering such fast connections. As countries ramp up their first LTE networks, they initially have few customers and large amounts of capacity. As consumers adopt smartphones and 4G service plans, they begin filling up those networks, causing speeds to gradually decline.

The final grouping of cities all had average 4G download speeds at or below the global average of 16.9 Mbps. Hong Kong joins the Southeast Asian cities such as Kuala Lumpur, Manila, Bangkok, Phnom Penh and Jakarta in this category. While their speeds are nothing to brag about, Southeast Asia has other 4G priorities at the moment. A notable trend we’re tracking in the region is the intense focus on 4G availability over 4G speed. As 4G connections are far superior to 3G connections, Southeast Asia’s operators seem intent on making LTE services accessible to the vast majority of their customers before they turn their attention to raw speed.

If you live in Asia or travel here, be prepared to have varyig levels of service when you pull put your smartphone.