The majority of Nepal has excellent internet connectivity that is affordable and available with your mobile data. Most of the cities like Kathmandu, Pokhara, Chitwan, Lumbini, and others offer free WiFi to visitors, but if you're considering a trekking trip and are unsure about which SIM card to get, this website will be very beneficial. There are now two firms in Nepal that offer SIM cards for mobile phones: Nepal Telecom (NTC) and Ncell. Depending on where you are trekking, you might want to choose the SIM card wisely, as these SIM cards provide coverage in certain places. Generally speaking, if you are planning a trekking or climbing trip in the Annapurna, Manaslu, or Upper Mustang regions, we advise you to have an NTC SIM card for both calls and internet. If you are planning a trip to the Everest region, then Ncell has a wider coverage, but in some areas above 4000 meters, none of these carriers might have signals.
In order to save mobile data, and where your preferred carriers don't work properly, the teahouses along the trekking routes offer both paid and prepaid wifi cards. You can buy these wifi cards for your urgent needs. Please be advised that using the internet in the Himalaya may not always work as you expected, even if you bought a prepaid wifi card. Additionally, none of these may work in the event of inclement weather. However, with the exception of really high elevations, most Himalayan trekking routes now have internet service, so you won't need to spend a lot of time disconnected throughout your trek.