How much data Netflix and streaming really use

Streaming Netflix uses roughly 0.3 GB an hour on its saving setting, roughly 0.7–1 GB on the middle one, roughly 3 GB at high quality and roughly 7 GB an hour in 4K — which means two episodes at high quality can cost more than everything else you did all day put together. These are planning estimates rather than measurements from your handset, and the other streaming services land in much the same range because they compress video in much the same way.

The common misconception is that streaming to a phone is automatically cheaper than streaming to a television. The screen is smaller, but what determines the volume of data is the resolution the app decides to send, not the size of the glass you are holding. Given a strong connection and no ceiling, it will happily push something very sharp indeed onto a six-inch screen without asking.

Rough figures for streaming and downloading

The row most people overlook is the last one. Deciding what to watch has a price, because the browse screen plays a trailer for everything your thumb pauses on. Ten minutes of not being able to choose costs about what twenty minutes of actually watching would on the saving setting.

Setting the app's data usage

Netflix keeps this switch somewhere people rarely look — under the profile rather than under a general settings page. The path is the same on iOS and Android, and it is worth doing before you travel rather than after you notice the data has gone.

1. 1Open your own profileTap My Netflix or the profile icon in the bottom corner and open the settings menu. Check that you are in your own profile and not someone else's in the household.
2. 2Set Mobile data usageFind App Settings and open Mobile data usage. Turn Automatic off and choose Save data. This applies only on mobile networks and leaves Wi-Fi playback alone.
3. 3Switch on Wi-Fi Only for downloadsOn the same screen, under Downloads, leave Wi-Fi Only on for the whole trip. That switch is what stops a half-finished download from becoming an expensive surprise when you leave the hotel.
4. 4Download the night before a travel dayThe night before a long train or bus day, pull down three or four episodes on the hotel Wi-Fi. Choose Standard rather than High and each one lands at roughly 400–700 MB instead of several gigabytes.

Downloading beats streaming, almost always

On a trip, downloading beats streaming for two reasons that have nothing to do with data. It plays where there is no signal, which on a metro, in a tunnel or on a plane is the normal condition. And it plays at full quality without stalling, because the file is already on the phone. The data saving is a bonus that happens when the download ran on Wi-Fi.

• Download more than you think you will watch. Unused hotel Wi-Fi costs nothing, while having nothing to watch on a four-hour train does.
• Check your free storage first. A whole season at high quality can run to tens of gigabytes — a different problem from data, but one that wrecks the same plan.
• Downloads expire. Grab them too far in advance and they may refuse to play when the moment comes, so download close to the travel day.
• The catalogue you see changes with the country you are in, so something you saw at home may simply not be listed abroad. That is another argument for downloading before you go.

If you really do have to stream

Sometimes it is unavoidable — the hotel Wi-Fi is too slow to download, or the thing you want went up this morning. If you must stream, put it on Save data, pick from your saved list rather than browsing, and switch off autoplaying previews if your app offers that. Those three together usually cut the figure by more than half.

Wi-Fi versus cellular: why the numbers swing so much

With adaptive bitrate, Netflix climbs toward the ceiling of whatever quality tier you have chosen as long as the connection stays steady. A strong, stable hotel Wi-Fi tends to push playback near the top of that range for the whole episode. On a roaming cellular connection, the app is more cautious and quietly trims the bitrate the moment it senses a weak signal or high latency, even with the identical Automatic setting active. That is why the exact same setting can cost noticeably different amounts of data on two different connections.

The problem almost nobody accounts for is walking out of hotel Wi-Fi range mid-episode and onto cellular. The player has to rebuffer immediately at the new connection's tier, which means some of the picture already fetched ahead on Wi-Fi gets thrown away and re-requested at a lower bitrate. If you know you are about to leave Wi-Fi range while watching, pausing for a moment and resuming once you are firmly on the new network helps, and so does manually locking the quality down in advance from the gear icon during playback, so there is no mid-episode jump to smooth over.

Common traveller mistakes with Netflix

The biggest silent leak is Autoplay next episode, because it never waits for you to decide. The instant the credits on one episode start, the app begins buffering the next one automatically. If you set the phone down after finishing an episode, it may have loaded half of the next one before you come back and close the app. Turn it off from your profile under Account or App Settings, looking for Autoplay next episode in a series, and switching it off.

The next most common mistake is assuming downloads are always safe once made. Some accounts have Smart Downloads switched on, which deletes a watched episode and fetches the next one automatically in the background. If Only download using Wi-Fi is not also enabled, that automatic fetch can happen over cellular without you noticing. Another mistake is switching to a different profile on the same account, such as a child's profile, which may be set to a far higher quality than your own. The data-saving setting lives at the profile level, not the account level.

• Before leaving the room, switch Autoplay next episode off and confirm Only download using Wi-Fi in the profile you will actually use on the trip, not whichever profile the account opens to by default.
• Do not idly scrub the progress bar looking for a scene you remember, since every drag loads a fresh preview thumbnail. If you need to find a scene, use the episode list to jump to a title instead of dragging around inside one.
• If you cast to the room's television, check first that the TV is on the same Wi-Fi you are actually using. Some hotel televisions run on the building's own internal network separate from the guest Wi-Fi, which quietly turns your phone into the thing streaming over cellular instead of Wi-Fi.
• Do not assume one profile behaves identically on every device. Video quality settings are stored per device you have signed in on as well, not set once and done everywhere.

Budgeting a realistic day of Netflix while traveling

A real travel day is almost never a single resolution watched continuously. It tends to mix downloaded episodes played on a bus or plane with live streaming once back at the room and connected to Wi-Fi, so the day's total depends more on the ratio between the two than on total hours watched.

Someone who makes a habit of downloading before leaving the room each morning spends far less real data than someone who streams the moment they feel like watching, because the download happens once on Wi-Fi, while live streaming costs data every single time it is opened, whether or not it is the same episode just watched.

Because the ratio between downloading and live streaming matters this much, a more targeted approach is to decide in advance which parts of the day will rely on downloaded episodes, and save live streaming only for the times you already know Wi-Fi will be available.

Work out your streaming budget