File transfer not working? Fixes by symptom
Last updated: July 29, 2026
Most browser transfer problems come from one of three places: the network refusing to let two devices talk, the phone suspending the page, or the operating system deciding what a download is allowed to do. Below are the symptoms people actually hit, with the cause and the fix for each.
The two devices never connect
It sits on "connecting" forever
The two browsers cannot find a path to each other. Common causes, most likely first:
- A VPN on either device. This is the most frequent single cause. Turn it off on both sides and retry.
- A corporate or school network that blocks peer-to-peer connections and the fallback relay. If the network is managed, you will not be able to change this — use a personal hotspot instead.
- A strict firewall on a work laptop.
- The other page was closed. Both sides have to be open at the same time; there is no server holding the file, so there is nothing to connect to if one side leaves.
The link or PIN says it is invalid
Sessions are deliberately short-lived, and a PIN expires a few minutes after it is created. If you scanned a code from a screenshot taken earlier, it is gone. Start a fresh transfer.
A link can also only be used once. If someone else opened it first, or you opened it in a second tab, the session is already claimed.
The QR code will not scan
Raise the brightness on the screen showing the code, hold the camera 15 to 20 cm away, and give autofocus a moment. Dark mode plus a dim screen is the usual culprit. Failing that, type the PIN — it is faster than fighting a camera.
It connects, then goes wrong
Progress stops partway and never resumes
Almost always a suspended page. Phones aggressively pause background tabs to save battery, and a paused tab cannot send or receive.
- Keep the browser in the foreground on both devices for the whole transfer.
- Extend the screen auto-lock interval before starting something large.
- Do not switch apps to check something "quickly" mid-transfer.
It transfers, but painfully slowly
You are almost certainly on a relayed connection rather than a direct one, which caps you at the sender's upload speed. Check whether both devices are on the same Wi-Fi network, whether one has fallen back to mobile data, and whether a VPN is running. Full explanation in why file transfers are slow.
The connection drops when I lock the phone
Expected behaviour, not a fault. Locking the screen suspends the page and tears down the connection. There is no way around it from a web page — keep the screen on.
The transfer finished but the file is not there
On Android: only the first of several files saved
Chrome allows a page to save one file automatically, then asks permission before it saves more. If that prompt is missed or dismissed, the rest are blocked silently — the page thinks they were delivered.
Fix: open Chrome's site settings for the site (tap the icon left of the address bar → Permissions) and allow Automatic downloads, then send the batch again.
On iPhone: it opened a preview instead of saving
iOS only writes a file to storage in response to a deliberate tap. A file that arrives is offered with a Save button; tapping it opens the share sheet, where you pick Save to Files, Save Image or Save Video. If you dismiss the share sheet, nothing is saved — tap Save again.
On Android: where did it go?
Into the Downloads folder, not the gallery. Photos and videos saved through a browser do not appear in the camera roll timeline automatically; open Files → Downloads, or move them into the pictures folder.
On desktop: the browser blocked it
Check for a blocked-download indicator in the address bar, and check whether an extension or corporate policy is intercepting downloads.
The file arrived but is broken
If the integrity check reports a mismatch when the transfer completes, the file is truncated or corrupt — do not use it, send it again. This is rare, and usually means the connection dropped right at the end.
If the file arrived intact but will not open, it is a format problem rather than a transfer problem. The usual suspects are HEIC photos and HEVC video from an iPhone landing on a device that cannot decode them. Ask the sender to switch Settings → Camera → Formats to Most Compatible, or install the matching codec. Details in the iPhone to Windows guide.
Things that are not faults
- The page returns to the start after a long idle period. Sessions do not stay open indefinitely.
- The sender has to stay on the page. There is no copy on a server, so the sending device is the source until the transfer completes.
- The receiver has to open the link. Nothing is pushed to a device without a person on the other end opening the transfer page.
Still stuck?
The single most effective reset: put both devices on the same Wi-Fi network, turn off every VPN, keep both screens on, and try again. That resolves the large majority of failures. If it does not, get in touch with what you saw and on which devices.