Tresorit Send and StrongFolder both appear in answers about "secure file transfer", but they make files safe in opposite ways. Tresorit Send encrypts files end to end and stores the encrypted copy for a week. StrongFolder sends files directly from your browser and stores no copy at all. This StrongFolder vs Tresorit Send comparison lays out the facts so you can pick by your actual risk.
How do StrongFolder and Tresorit Send compare?
Tresorit Send facts as of 5 November 2026, from Tresorit's help center (Tresorit Send overview and FAQ) and send.tresorit.com (sources at the end). "Not stated" means Tresorit's own pages don't say.
| StrongFolder | Tresorit Send | |
|---|---|---|
| Model | Peer-to-peer, browser to browser | End-to-end encrypted cloud link |
| Stored on a server | Never | Encrypted copy for 7 days |
| Size limit | None set by the service | 5 GB per upload, up to 100 files |
| Downloads | Several recipients from one link while you share | Up to 10 downloads per file |
| Link lifetime | While you share; Stop Sharing ends it | 7 days, or revoke earlier |
| Sender can go offline | No — tab stays open | Yes, after the upload |
| Encryption | DTLS in transit (WebRTC) | Client-side, end-to-end, AES-256; key in the link |
| Password on a link | Not at the moment | Optional |
| Notification when opened | Shows how many users are connected | Optional e-mail |
| Whole folders with structure | Yes, no ZIP | Not stated |
| What you provide | Nothing (Google sign-in optional) | Your e-mail address, verified via the admin link |
| Data location | Files not stored | Microsoft Azure data centers in Ireland |
| Price | Free | Free ("freemium product") |
How does Tresorit Send protect files?
Tresorit's FAQ says Tresorit Send uses client-side, end-to-end encryption: files are encrypted with AES-256 on your device before upload, and the decryption key is part of the download link and never stored on Tresorit's servers. You can add a password and, for best protection, send the link and the password through different channels.
The encrypted copy sits in Microsoft Azure data centers in Ireland. Links are available for 7 days, then files are deleted automatically, and Tresorit says stored content and related metadata are removed from its system 14 days after a link expires. You can revoke a link at any time from the admin link sent to your e-mail.
How does StrongFolder protect files?
By not keeping them. Files are never uploaded to or stored on a StrongFolder server. WebRTC encrypts every data channel with DTLS, so the file stream is encrypted in transit on every connection. If a direct connection is impossible (strict corporate firewall, some mobile networks), the encrypted stream passes through a StrongFolder relay (TURN) server. The relay forwards the data and does not store it.
To create the link, the service keeps transfer metadata: file and folder names, sizes and the number of files. We describe our protection as encryption in transit, not end-to-end encryption with your own key — there is no password option at the moment, so treat the link like a key and click Stop Sharing when the recipient is done. See security and the DTLS glossary entry.
Which is more secure: E2EE cloud or P2P without storage?
They answer different threats.
- Worried about a stored copy being breached? Tresorit Send's copy is encrypted with a key only the link holds. StrongFolder has no copy at all.
- Worried about the link leaking? Tresorit Send adds an optional password, open notifications and revocation. With StrongFolder, a leaked link works only while you are sharing; stopping sharing ends it.
- Bound by rules on where data sits? Tresorit names its data location (Ireland). StrongFolder doesn't store file contents anywhere.
Many teams use both: an E2EE cloud link for a contract the client opens next week, a direct transfer for a 60 GB folder of raw footage today. More in secure file sharing and P2P vs cloud file transfer.
Free · in your browser · no sign-up
What if my files are larger than 5 GB?
Tresorit's help center lists 5 GB per upload and 5 GB in total at once, with up to 100 files. Larger transfers need several links or another tool; for more storage and advanced features, Tresorit points to its paid plans.
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. Because files stream from your disk, a big video project or a folder with thousands of files is sent the same way as one document. See how to send large files and StrongFolder limits.
Can Tresorit Send keep a folder structure?
Tresorit's help center describes selecting files for upload and doesn't describe keeping a folder tree (as of 5 November 2026). For deep project folders, zipping first is the usual workaround with upload services.
StrongFolder sends folders as folders. Folders are sent as folders: subfolders and file names are kept, nothing is zipped. Saving a whole folder with its structure uses the File System Access API: Chrome, Edge, Opera and other Chromium browsers on a computer. Other browsers can download the files one by one or as a ZIP. More in how to send a folder without zipping.
When is Tresorit Send the better choice?
Choose Tresorit Send when:
- you need to send and go offline — the recipient can download any time within 7 days;
- end-to-end encryption is required by your policy or your client;
- you want a password, an e-mail when the link is opened, and the option to revoke;
- the files fit in 5 GB and 100 files;
- your sender identity matters — the verified e-mail on the download page reassures the recipient.
Tresorit Send alternative: when is StrongFolder the better choice?
Choose StrongFolder when:
- the transfer is over 5 GB or more than 100 files;
- you're sending a whole folder that must keep its structure;
- no copy should be stored anywhere, even encrypted, even for 7 days;
- you don't want to give an e-mail address — No account needed to send or receive. Signing in with Google is optional and keeps a list of your transfers.
- several people need the files at once: One link can be opened by several recipients; each downloads directly from the sender.
The honest trade-off: The sender's browser tab must stay open and online until the recipient finishes downloading — files come from the sender's device, not from a server. See why the sender stays online.
How do I send with StrongFolder?
- Open strongfolder.com or click the StrongFolder Chrome extension.
- Choose files or a whole folder. Nothing is uploaded first.
- Copy the link or show the QR code and send it privately.
- Keep the tab open while recipients download, and click Stop Sharing when they're done.
See how it works.
Summary
Tresorit Send is end-to-end encrypted cloud sharing: up to 5 GB and 100 files, kept for 7 days, 10 downloads per file, with passwords, notifications and revocation — ideal when the recipient opens files later. StrongFolder is direct transfer with no stored copy, no size limit set by the service and folders kept as folders, as long as your tab stays open. See also StrongFolder vs Wormhole and WeTransfer alternatives.
Sources
Checked on 5 November 2026: Tresorit Send overview (help center) · Tresorit Send FAQ (help center) · send.tresorit.com