Streaming vs. downloading: Which uses more battery and data?

Although some people are pushing back, a lot of us are dependent on streaming services for our movies and music. There's an obvious incentive — you get a massive library for a (relatively) cheap monthly fee and the ability to access that media from virtually any device with an internet connection. Conversely, owned downloads and physical media can be pricey and not terribly portable.

Many streaming services do offer a middle ground of sorts, letting you cache songs, videos or podcasts so you can play them with or without an internet connection. But let's say you're most concerned with efficiency and not the soundtrack to a remote camping expedition. Does it still make more sense to download in advance, or should you stream whenever possible?

The quick answer is that downloads (of all stripes) are usually the most efficient option when it comes to battery and usage. But there may be times when streaming is preferable, or possibly the only option.

For anything you enjoy on a regular basis, downloads win. While there's going to be an initial (and possibly intense) surge of battery and bandwidth consumption, that's vastly outweighed by the non-existent effort for subsequent plays. You should always cache over Wi-Fi, incidentally, since it's usually faster, and a way to avoid bumping up against the data caps that many cellular providers continue to impose on their plans.

It's only when you're talking about one-time plays that streaming is in any way efficient. If you hit Stop or Pause partway through a video or playlist with no intent of coming back, you may consume less power and data. We say "may" because all streaming apps perform a base amount of caching, whether or not you deliberately save anything. Depending on where you halt during playback, your device may already have a complete video or playlist in memory, which is quickly going to be wasted.

Really, the only reason to avoid downloading is storage space. Just a few cached playlists in a music app can consume several gigabytes, speaking from personal experience, and that's without factoring lossless options into the equation. In app settings, Spotify notes that its lossless downloads can consume up to 1 GB per hour of playback — which will probably make downloading your entire library impractical, if not impossible.

Perhaps the easiest way to rein things in is by adjusting media quality. Returning to the Spotify example, even scaling back from lossless quality to "Very high" (320 kbps) drops data consumption from 1 GB per hour to just 0.14 GB, according to the music streaming site. Lower data use naturally means reduced battery drain, since caching is faster. Similar principles apply to video apps, although they tend to manage quality via resolution options instead of bitrate. All else being equal, a 480p or 720p version of a video has a far smaller footprint than 1080p. Depending on your app and device, 4K downloads may not even be an option.

You should only scale things back so far. While lossless and 320 kbps are virtually indistinguishable in audio, you'll notice a lack of clarity by the time you drop to 160 kbps. Similarly, although you're probably not going to spot the difference between 1080p and 4K on something as small as a phone or tablet, 720p is below the sharpness of most displays.

There may be smarter ways of reducing battery and data use, such as lowering screen brightness, and being more selective over what you consume in general. Your life doesn't always need a soundtrack or video wallpaper. And if you limit the number of apps, podcasts and playlists on your device, there's less to update in the background.