Stuck on "Connecting"? Why Some Networks Block Direct Transfers

Sometimes the receiver opens the link, both screens say “connecting”, and nothing happens. No error, no progress, just waiting.

This is nearly always the network, not the file and not the browser. Here’s why it happens and what to do.

Why direct connections fail

Your devices almost never have a public internet address of their own. Your router has one, and it shares it with everything in your home using something called NAT (network address translation). It’s a bit like an office building with one street address and lots of internal extensions.

For two browsers to talk directly, each one needs to find a route through the other’s NAT. Browsers have clever tricks for this (we explain them in what WebRTC actually is), and on most home networks they work. But some networks make it impossible:

• Corporate and university firewalls often block the kinds of connections peer-to-peer uses, on purpose.
• Mobile carriers frequently put thousands of phones behind one shared address (called carrier-grade NAT). Two phones on mobile data can struggle to find each other.
• Some VPNs block peer-to-peer traffic or route it in ways that break the connection.
• Hotel, airport and café Wi-Fi sometimes isolates every device from every other device for security.

When this happens, there’s no direct path to find, so the connection never gets started.

The quick fix: switch to Bolt Tunnel

This is exactly why BoltShare has two modes. Bolt Tunnel doesn’t need a direct path. Both browsers connect outward to our relay over a normal secure web connection, the same kind every website uses, which almost no network blocks. The relay passes the file from one side to the other as it arrives, without storing it.

Bolt Tunnel is the default for this reason. If you’d switched to Direct P2P and got stuck, start a new share with Bolt Tunnel selected.

If you want Direct P2P to work

Maybe you’d rather keep the file off any relay. Some things to try:

1. Get one side off the restrictive network. If the receiver is on office Wi-Fi, could they switch to their phone’s hotspot for a few minutes? Only one side usually needs to be on a friendly network.
2. Pause the VPN on both ends for the transfer.
3. Avoid mobile data on both ends. One phone on mobile data and one computer on home broadband often works. Two phones on mobile data often doesn’t.
4. Use the same Wi-Fi if you’re in the same place. Two devices on the same home network can almost always connect directly, unless the router has “client isolation” or “AP isolation” switched on (common on guest networks).

Other things that look like a connection problem

A few things can masquerade as connection failures:

• The sender closed the tab. BoltShare doesn’t store files, so the sender’s tab is the file source. If it’s closed, the link has nothing to connect to.
• The sender’s laptop went to sleep. Same effect. A sleeping computer can’t send anything.
• The link expired. Share links stay valid while the sender’s session is open. If both of you left for a while, the session ends and you’ll need a fresh link.
• An ad blocker or privacy extension is blocking the connection to our signaling server. Try a private window with extensions disabled to rule this out.

If none of this helps, contact us with the browser and network type on each side (home Wi-Fi, office, mobile data). The pattern usually tells us what’s in the way.