In this case, the limits are 10,000 songs across 5 devices. Click the three-dot icon and select the Shar e option, then click the Copy Spotify URL button.
Open the Spotify Web Player or the Spotify app on your computer and locate the playlist to download. This is so the Spotify app can confirm you still have an active subscription, and therefore have rights to the downloaded songs. Head to the website of Soundloader, and you download a playlist from Spotify Web Player online for free. If you find you can't play playlists you're already downloaded, be aware you'll need to connect your device to the internet at least every 30 days.
If you find you can't download everything, you may need to create some more selective playlists and download those using the instructions above. Like on-device formats, Spotify's high-quality audio requires a non-trivial amount of storage. If you're simply enjoying the free offering (you'll know if you are if you hear advertisements), you'll need to upgrade to Spotify Premium in order to utilize this feature.