It’s not hard to find free Wi-Fi at a North American airport these days, but more often than not, it’s a sluggish affair.

Passengers at Denver International Airport don’t have any complaints, though. In fact, that facility has the fastest free airport Wi-Fi in the North America, according to a new study from Speedtest. The site, which allows users to test their own bandwidth speeds, says downloads at DEN have actually gotten 27% faster since January, making it the airport with the fastest WiFi in the world.

Vancouver International Airport came in second free Wi-Fi rankings, followed by Philadelphia, San Francisco and Seattle-Tacoma.

It is worth noting, though, that (with the exception of Denver) all of the airports listed showed speeds that were slightly slower than the national average of all Wi-Fi connections, including those in private homes.

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“Slightly slower” is still notably faster than many other North American airports, though. Hartsfield-Atlanta, the world’s busiest airport, ranked second to last in the study, with speeds that were just 5% that of a typical home Wi-Fi connection. New York’s three airports all came in at roughly a quarter of the average home speed.

Others that fell far short of the connection speed most people are used to included Detroit, Los Angeles, Miami, Chicago’s O’Hare, and Las Vegas’ McCarran International.

The worst airport for Wi-Fi in North America, though? That dubious honor goes to Montreal’s Pierre Elliott Trudeau International Airport, with speeds that are less than 4% of the average speed in Canada.

The takeaway? If you’ve got work to Atlanta, Montreal or Toronto (the third slowest city), make sure your laptop or tablet is plugged in. Otherwise, you’re facing some major battery drain.