Transferring files
Every transfer runs between your browser and your own computer, in 64 KB pieces, encrypted at both ends. The server passes the pieces along without being able to read them, and stores none of them.
Sending files to your computer
Use Upload, or drag files from your desktop onto the list. Both routes reach the same place: the folder you are currently looking at.
- One file is streamed as it is. The agent creates the destination file first, acknowledges, and only then does your browser start sending — so a transfer either starts properly or fails immediately.
- A folder, or several files at once, is packed into a ZIP in your browser and sent as one transfer. The agent extracts it on arrival and deletes the archive. Folder structure survives; empty folders inside the selection do not.
Naming collisions are handled differently by the two routes, which is worth knowing before you drag a folder: a single file is given a numbered name rather than replacing what is there, while a ZIP is extracted over the destination and overwrites files of the same name.
Bringing files back to the browser
Select a single file and press Download or Enter. The file is streamed to the browser and assembled there, then saved by your browser as usual.
Because it is assembled in memory first, a multi-gigabyte download needs that much room in the browser — this is the practical ceiling on the web app, and it is lower on a phone than on a desktop.
Downloading a whole folder from the remote machine is not offered; select the files you want.
The limits that can stop a transfer
| Limit | Where it lives | What you see |
|---|---|---|
| Plan file-size limit | The server, for every upload | File size limit exceeded (max N MB for your plan) |
MaxDownloadMb | The agent, default 2048 MB, 0 removes it | The download is refused by your own machine |
TransferSpeedLimitKbps | The agent, default 0 (no cap) | Transfers are slower than the line allows |
ChunkSizeKb | The agent, default 64 | Nothing visible; it tunes throughput |
The agent-side settings are yours to change — see configure the agent by hand. The plan limit is not; it is described in plans and quotas.
The browser checks the plan limit before starting, so an oversized file is refused up front rather than after ten minutes of uploading. The server checks it again while the bytes flow, because a client-side check protects nobody.
When a transfer stops halfway
- The device goes offline mid-transfer. The partial file stays on the remote machine under the name it was being written to. Delete it and start again.
- Nothing happens after you press Upload. The agent has 30 seconds to acknowledge before the browser gives up. This usually means the agent is not actually running — work down the device shows as offline.
- You close the tab. The transfer stops. There is no resume, in either direction.
Why transfers can feel slow
The path is browser → relay → your computer, so the slowest link decides: usually the upload speed of the connection your agent is on, which on a home line is a fraction of its download speed. A large transfer to a home machine is slow for the same reason sending an email attachment from home is slow.
If the agent runs on a machine with TransferSpeedLimitKbps set, that cap applies on top.
What the server keeps
Nothing. The relay forwards encrypted pieces and holds no copy — which is also why there is no transfer history and no "resume where you left off". The only durable copies are on your own machine and wherever your browser saved the download.
Updated 2026-08-06