Every product makes a trade-off somewhere. Ours is written on every how-to page of this help center, and I would rather say it loudly than hide it in small print. The trade-off of P2P file transfer is this: when you send files with StrongFolder, your browser tab has to stay open until the recipient finishes downloading. This post is about why we accepted that, when it is the wrong deal for you, and how to make it painless when it is the right one.
What exactly does P2P ask of you?
One thing: stay online. StrongFolder sends files directly from your browser to the recipient's browser over WebRTC. Nothing is uploaded in advance. Files are never uploaded to or stored on a StrongFolder server.
That means your device is the only source. If you close the tab, put the laptop to sleep or lose your Wi-Fi, the source disappears and the transfer stops. The link works while the sender keeps sharing. When the sender clicks Stop Sharing or closes the tab, the files are no longer available.
The same goes for the other side: if the recipient's computer falls asleep, they stop receiving. A direct transfer is a short appointment between two devices, and both have to show up.
Why did we choose it anyway?
Because the alternative — keeping a copy on our servers — is exactly what creates the problems I started StrongFolder to fix.
- No upload wait. With a stored-copy service, the recipient can't start until your upload has finished. Upload 50 GB at 50 Mbit/s and that is 50 × 8,000 ÷ 50 = 8,000 seconds — about 2.2 hours — before the link is even ready, and then the recipient's download comes on top. With a direct transfer, the download starts the moment the recipient opens the link.
- No stored copy. There is no file on a server to leak later and no retention period to read about. To be precise about what we do keep: To create the link, the service keeps transfer metadata: file and folder names, sizes and the number of files.
- No size cap from us. Storage costs money, which is why storage-based services cap file sizes or charge for larger ones. We don't store, so we set no limit. No size limit set by StrongFolder. The practical limits are free disk space on the recipient's device, connection speed, and how long both devices stay online.
- Folders stay folders. Folders are sent as folders: subfolders and file names are kept, nothing is zipped.
There is also a point people often miss: a cloud link asks you to stay online too — during the upload. The real difference is whose schedule you depend on. With a cloud upload you are online for the upload and then free to leave; with P2P you are online for as long as the recipient is downloading. If the recipient opens the link right away, the time you spend online is about the same — but the data travels once instead of twice.
When is a cloud link the better tool?
I want this help center to be useful, not just persuasive, so here is where I would not use StrongFolder myself:
| Situation | Better tool | Why |
|---|---|---|
| You leave in ten minutes and the files are a few gigabytes | A transfer service that stores a copy | Upload once, close the laptop, the recipient downloads later |
| The recipient is in another time zone and will download tomorrow | A cloud drive link | The copy waits for them on the server |
| Many people need the files for weeks, with previews and comments | A cloud drive or project platform | Shared access and browsing, not a one-off delivery |
| Long sends from a phone | A computer, or a cloud app | Mobile browsers pause pages in the background |
| Terabytes over a slow upload, recipient in the same city | An external drive | 2 TB at 20 Mbit/s is 800,000 seconds — more than nine days |
If one of those rows describes your situation, a stored copy is the right trade-off and you should take it. The full comparison is in P2P vs cloud file transfer, and WeTransfer alternatives lines up the services side by side.
How do I make staying online painless?
For everything else — the recipient is ready now, the files are big, you'd rather not upload them anywhere — staying online is mostly a matter of preparation:
- Do the math first. Size in GB × 8,000 ÷ your upload speed in Mbit/s = seconds. 20 GB at 100 Mbit/s is about 27 minutes; 120 GB at 50 Mbit/s is about 5.3 hours. Real transfers run somewhat slower because of overhead, so add a margin. On many home connections the upload number is far lower than the download number — check it with any speed test.
- Plug in. Battery-saving modes are more aggressive about sleep.
- Turn off sleep, not the screen. A dark screen is fine; sleep stops the transfer. On
Windows, set sleep when plugged in to Never for the session (or use the free PowerToys
Awake). On a Mac, run
caffeinate -iin Terminal until the transfer ends. - Keep the tab active. In Chrome, open Settings → Performance → Always keep these
sites active and add
strongfolder.com, so Memory Saver never deactivates the tab. - Use a cable. Wi-Fi is fine for a few minutes; over several hours an Ethernet connection is simply more stable.
- Pause competing uploads. Cloud backup, photo sync and video calls share the same upload bandwidth.
- Agree on a time window with the recipient, and split very large sends into a few folders. If something drops, you only redo one batch.
Step-by-step settings for Windows, macOS and browsers are in Why the sender stays online.
Free · in your browser · no sign-up
Is the trade-off worth it?
For the transfers StrongFolder was built for — a finished video for a client, a project folder for a colleague, a photo archive for family who are waiting for it — I think it clearly is. Keeping a tab open for an hour is a small price for no upload wait, no copy on someone else's server and no limit on size.
For the cases in the table above, it isn't, and I'd rather you use the right tool than the wrong one with our name on it. If you hit a situation where the trade-off hurts and none of the tips help, write to me at info@strongfolder.com — that is exactly the kind of feedback that shapes what we build next.