Why file sharing fails on mobile data, and how to fix it

By Thavasi · Updated 30 October 2026

A direct file transfer works perfectly on home Wi‑Fi, then gets stuck at "Connecting…" when one phone is on mobile data. This isn't a bug in the app. It's how mobile networks are built.

Why it happens

To send a file directly, one device has to be able to reach the other. On home Wi‑Fi, both devices sit on the same local network, so they find each other easily.

Mobile networks work differently. To save internet addresses, operators like Jio, Airtel and Vi put many customers behind one shared address (called carrier-grade NAT) and block incoming connections. Your phone can reach websites, but other devices can't reach your phone directly. Two phones on mobile data usually can't connect to each other at all.

This affects every browser-based file sharing tool, not just one.

Fix 1: Use the same Wi‑Fi

Connect both devices to the same Wi‑Fi network. This is the fastest option, and it uses no mobile data for the file itself.

Fix 2: Use a hotspot

No shared Wi‑Fi? Turn on one phone's hotspot and connect the other device to it. The two devices are now on the same small network, so they can connect directly. The file travels between them through the hotspot and doesn't use mobile data.

Some phones block hotspot devices from talking to each other. If it doesn't connect, try the other phone's hotspot.

Fix 3: Add a relay for different networks

When the devices really are in different places, the data has to pass through a relay (a TURN server). WifloShare lets you use your own free relay from Cloudflare, which takes about 10 minutes to set up once. Only one of the two devices needs it.

Read the relay setup guide

Fix 4: Check the computer's network settings

• Windows: set the Wi‑Fi network to Private (Settings → Network & internet → Wi‑Fi → your network). On "Public" networks, Windows blocks incoming connections.
• Brave browser: its Shields block direct connections. Turn Shields off for the site, or use Chrome, Edge or Firefox.
• Office, college or guest Wi‑Fi sometimes blocks devices from talking to each other. A hotspot usually gets around this.

Quick checklist when a transfer won't connect

1. Are both devices on the same Wi‑Fi or hotspot?
2. Is the sender's page still open, with the screen on?
3. On Windows, is the network set to Private?
4. Are you using Brave or a privacy extension?
5. Different networks? Is a relay set up on one of the devices?