What does cache music while streaming mean?

Music streaming services like Spotify, Apple Music, and Pandora allow users to listen to millions of songs online through an internet connection instead of downloading music to own locally. These services rely on constant data streaming to play songs on-demand. To provide a smooth listening experience, music streaming apps utilize a process called caching to download and temporarily store songs on a device.

Caching refers to keeping a local copy of frequently accessed content like songs, videos, web pages, and images. By caching music files that a user listens to often, streaming apps can reduce delays, interruptions, and reliance on a consistent internet connection during playback. This allows for a more seamless listening experience. The streaming app automatically manages the cache in the background, downloading songs it predicts the user will want to hear offline.

How Music Streaming Works

Music streaming allows users to listen to music from a service’s servers over the internet, instead of downloading files to a device. When a user selects a song to play, the streaming service sends small portions of the audio data over the internet to the user’s device. This allows the music to begin playing almost instantly, without needing to wait for the full file to download first.

As Soundcharts explains, “Music streaming works in a very simple way: a streaming service delivers data to a streamer in small amounts so that the user can get pre-loaded audio instantly. While one piece is playing, the next is buffered. Buffering refers to a small amount of data being stored on the receiving device to mitigate potential interruptions.”¹

This on-demand model provides a more convenient listening experience compared to traditional radio or owning music files. Users can immediately access vast catalogs of music at any time, from any location, without needing to manually manage and store files locally.

Buffering and Interruptions

When music streaming online, the file is not completely downloaded before it starts playing. Instead, it relies on buffering to download a few seconds of audio ahead of time to try to avoid interruptions and lag

Buffering refers to the process of loading a small portion of the audio file into a “buffer” before playback begins. This buffer allows the playback to continue even if there are momentary drops or lags in the internet connection speed. Typically streaming services will try to buffer at least 10-30 seconds ahead of playback to help avoid interruptions.

However, if the buffer runs out because the connection speed has slowed, you may experience choppiness, stuttering, or even full interruptions in the playback while more of the file downloads. Frequent buffering is usually a sign of an unstable or slow internet connection.

Buffering allows streaming with minimal lag, but can still result in playback issues if the connection has problems. Streaming services aim to minimize buffering issues by caching as much as possible in advance.

As noted in [1], buffering during streaming often indicates WiFi connection problems. Per [2], high network latency can also increase buffering frequency. Users on forums like [3] report buffering and music interruption issues as well.

Caching Music Files

Streaming services like Spotify allow you to save or “cache” music on your device for offline listening. This means parts of the song files are temporarily downloaded and stored locally on your device’s storage. According to Quora, caching allows you to listen to songs without requiring an active internet connection. Only partial song data is stored to conserve storage space.

The portion of the song that is cached depends on the service. According to Lifewire, Spotify caches around 3 minutes worth of song data whereas Apple Music caches the entire song file. Caching provides a seamless listening experience by reducing interruptions and buffering issues you may experience while streaming.

Benefits of Caching

Caching music files offers two primary benefits for streaming music listeners. First, it helps reduce buffering and interruptions (Source). When songs are cached locally on a device, the music player can access them directly without needing to stream the files each time. This avoids delays from buffering as the song downloads. Second, caching enables offline listening options when an internet connection is unavailable (Source). Once music is cached, listeners can continue playback without interruption even when offline. This makes caching ideal for areas with spotty connectivity or for travelers.

How Much is Cached

The amount of music that is cached or stored locally during streaming varies significantly depending on the particular music service and settings. According to a Reddit user, Apple Music in particular seems to cache a large amount of streamed music which can take up significant storage space on devices [1]. However, an Apple support thread notes that Apple Music is designed to automatically delete cached songs when storage space runs low [2]. So the amount that is cached at any given time depends on available storage capacity.

Other streaming services like Spotify and Tidal also cache some amount of music, but give users more direct control over managing the cache size and deleting cached songs. For example, Spotify has a setting to limit the size of the cache [3]. So the amount cached will vary based on each user’s settings and storage availability. In general, streaming services are designed to minimize caching to only what is necessary to maintain a smooth listening experience.

Controlling Caching

Many music streaming apps allow users some control over how much music is cached on their device. This gives users the ability to manage their device’s storage and data usage.

In the SubStreamer app, users can adjust the size of the cache in the settings. They recommend keeping it under 2GB if you are worried about storage space.

The Amazon Music app also allows clearing the cache in settings under the Storage section (Amazon). This can free up storage space on your device when the cache gets too large.

Some users have requested more granular cache controls (Google support forums), like setting cache limits for individual songs or playlists. However, most apps do not currently offer this level of control.

Overall, users have some ability to manage cached music files, but options are still limited in most streaming apps. Clearing the cache entirely or adjusting its maximum size are the primary methods available to consumers.

Data Usage Implications

Caching songs can help reduce mobile data usage while streaming music. According to Reddit users, Spotify can build up a cache of several gigabytes in size by saving songs you’ve streamed previously [1]. The cache allows you to play those songs again without having to re-download them, which saves on data usage. Android Authority notes that streaming an individual song can use anywhere from 0.5MB to 8MB of data [2]. So by caching songs, you avoid that data expenditure when playing cached tracks.

However, the cache does take up storage space on your device. You may need to clear the cache periodically to free up storage, which will cause the songs to need to be re-downloaded next time you play them. So there is a tradeoff between data usage and storage space when it comes to caching streamed music.

Deleting the Cache

When you stream music on Apple Music, it caches (downloads) songs and albums locally on your device so that they load and play instantly without buffering or interruptions. This cached music takes up storage space on your device. If storage space is limited, or if you want to remove songs you no longer listen to, you can delete the Apple Music cache to free up space.

To clear the Apple Music cache on iPhone or iPad, go to Settings > General > iPhone/iPad Storage. Tap Music, then tap Edit. Select the songs, albums or artists you want to remove from the cache, tap Delete, then tap Delete Music to confirm.

On Android, go to Settings > Apps & notifications > See all apps > Apple Music. Tap Storage & cache > Clear cache. This will delete the entire Apple Music cache.

On desktop, quit the Apple Music app, go to the Music folder in Finder/Explorer, then drag cached files to the Trash/Recycling Bin to delete them. You can also delete the entire Music cache folder, but this will remove all offline music.

According to MakeUseOf, clearing the Apple Music cache can recover up to “several gigabytes” of storage space on your device [1]. Keep in mind that any songs you delete from the cache will need to be streamed again in the future, which uses more data.

Summary

In summary, caching music while streaming refers to temporarily storing parts of songs or entire tracks on a device as you listen to music through a streaming service. Streaming services do this to allow for uninterrupted playback if you lose connectivity or switch between tracks. The audio files are kept in a cache folder and will typically include songs you’ve fully listened to or portions of tracks you’ve started playing. Caching can prevent buffering issues and skips in playback. However, it uses storage space on your device and data if you’re streaming over a cellular network. You can manage the size of the cache and clear it out fully if needed. Overall, caching enables a smoother streaming experience.