What to KnowAdd your external source under Settings > Local Files > Show Local Files > Show songs from.You can't truly upload music to Spotify; instead, you're telling Spotify to watch specific folders for selected music from other sources.
This article explains how to have Spotify recognize and find your music from external sources.
The local music transfer feature only works on Spotify Premium subscriptions. You can add music in MP3, MP4, or AAC format.
How to Add Songs to Spotify
To clarify what you're doing here, you're not actually uploading music in the sense that you're sending it to Spotify's servers. Instead, you're adding your local music to directories on a desktop machine to Spotify, at which point it will include that content when it displays your collection.
Once Spotify is watching these folders, it will automatically make new songs you place into those folders available within the application.
Click your user menu in the upper-right corner of the app window.
Scroll down to the Local Files section and turn the Show Local Files toggle on.
A new section, Show songs from will now appear just below the toggle switch.
Click the Add a Source button to select a directory. Spotify will scan this directory and all of its sub-directories for supported music and playlist files, which will then appear in your Spotify library.
Repeat Step 5 as desired, if you have music in several different directories.
How to Download Local Spotify Music for Offline Listening on Other Devices
In addition to being able to play your local music on the machine where it's stored, you can also transfer it to other mobile devices signed into the same Spotify account.
The following steps will work on Spotify-supported versions of both iOS and Android, as well as Windows and macOS.
First, all the songs you want to transfer need to be included in a playlist. An easy way to get all your music on your mobile device is to create a playlist that contains every song.
Now, start Spotify on your other device, and make sure you're on the same local network as the machine where the music is stored.
Desktop and Android users can skip this step. If you're on an iOS device, you'll need to go to the Settings screen and scroll down to the Local Files section. Tap the Enable sync from desktop button.
You should see the Playlist(s) containing the local files among your other playlists. You may be able to identify them because you're listed as the 'artist' (congratulations!). Click on one of them to open it.
Like the Playlists from Spotify's catalog, there will be a Download toggle button.
Turning this toggle switch on will download the playlist, and all the songs it contains, to your device.
If you're not connected to the same network as the machine where the music's stored, the playlist will still download, but the songs won't be downloaded until you do hook up to the same network.How to Scan Songs on Spotify