Audiobookshelf downloads are slow away from home

Away from home, a download can’t go faster than your home internet’s upload speed. Your server sends the book out over your home connection, and most home plans upload far slower than they download.

So a book that downloads quickly on your home Wi-Fi can crawl on the train. If upload speed is the cause, the fix is to download at home before you leave. If your upload speed is fine and downloads are still slow, check the things below.

Why is it fast at home and slow outside?

At home, when the phone uses the server’s local address, downloads stay on your own network. Nothing goes out to the internet.

Away from home, every byte goes:

1. From the server out through your home internet’s upload.
2. Across the internet, sometimes through a relay or tunnel.
3. Into your phone over mobile data or someone else’s Wi-Fi.

The slowest of those three sets the speed. Your home upload speed is the first thing to check. Run a speed test at home and look at the upload number, not the download one. A plan that says “500 Mbps” may upload at 20 Mbps or less.

Is Tailscale going through a relay?

Tailscale tries to connect your phone straight to your server. A strict router, a firewall or CGNAT can block that. (CGNAT is when your ISP shares one public IP between many homes.) Then Tailscale sends the traffic through a relay. That’s a peer relay if you’ve set one up, or otherwise one of Tailscale’s own relay servers, called DERP. Tailscale says relayed connections are usually slower and one of the most common causes of slow speeds.

To check, start a download on your phone while it’s away from home and connected to Tailscale, then run this on the server:

tailscale status

Find your phone in the list:

• direct followed by an address: a direct connection. Good.
• relay "...": going through a DERP relay.
• peer-relay: going through one of your own peer relays.

tailscale ping your-phone-name tells you the same: via DERP(...) means relayed, and an IP address and port means direct. The first few pings often go through a relay while Tailscale sets up the direct path, so let it run a few times.

If it stays on a relay, the usual cause is the network at one end. Try a different network on the phone (mobile data instead of hotel Wi-Fi, or the other way round). If your home is behind CGNAT, a direct connection may not be possible, and Tailscale’s connection guide explains the options.

Can a tunnel slow down Audiobookshelf downloads?

A Cloudflare Tunnel or a Pangolin server sends every byte through another company’s or your own rented server before it reaches you. That adds distance. Users report that downloads through these can be slower than a direct connection, though how much varies a lot.

If you use a Cloudflare Tunnel, the Cloudflare Tunnel guide has a few settings to check. A reverse proxy on your own home server doesn’t add a trip like this, so it’s usually as fast as your upload allows.

Why are downloads slow or waiting on mobile data?

A weak or busy mobile signal is often slower than it looks. If downloads are slow in one place and fine in another, it’s probably the signal.

In SoundLeaf, Download over mobile data in Settings > Downloads is off to start with. If a download says Waiting for Wi-Fi, it isn’t slow: it’s waiting. Turn the setting on, or connect to Wi-Fi.

Download at home before you leave

The fastest fix is to not download over the internet at all.

• Download on your home Wi-Fi. Downloads in SoundLeaf are free. A downloaded book plays with no connection to your server.
• Turn on Smart Downloads. In Settings > Downloads, Smart Downloads downloads a book after you’ve listened to it for a while (10 minutes to start with). Start a new book at home and it starts downloading once you pass the threshold. Check it has finished before you leave. On mobile data it waits for Wi-Fi unless Download over mobile data is on.
• Leave the app. SoundLeaf keeps downloading after you switch to another app.
• Use your home address at home. If you’ve set up a domain or tunnel, SoundLeaf can still use the fast local address on your home Wi-Fi. See home and away addresses.

More on downloads in Downloads, and on listening without a connection in Listening offline. Still picking how to reach your server from outside? Listening away from home compares the options.