StrongFolder Limits & Requirements: Size, Browsers, Folders

Limits & requirements

StrongFolder sets no limit on file size, number of files or transfers. What limits a transfer in practice is the recipient's free disk space, both connection speeds, and how long the sender keeps the tab open. Saving a whole folder with its structure needs Chrome, Edge or Opera on a computer.

Is there a file size limit?

No. 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.

What actually limits a transfer?

Factor	Why it matters	What to do
Recipient's free disk space	The files are written to their disk	Check space before a large send
Sender's upload speed	A direct transfer can't be faster than it	Use a wired connection; avoid big uploads at the same time
Time both devices stay online	Files come from the sender's device	Keep the computer awake and the tab open
Recipient's browser	Saving whole folders needs the File System Access API	Recipient opens the link in Chrome, Edge or Opera on a computer
Network restrictions	Some networks block WebRTC	Another network, or ask the administrator

Which browsers are supported?

Task	Chrome / Edge / Opera / Brave (computer)	Firefox (computer)	Safari (Mac)	Mobile browsers
Send files	Yes	Yes	Yes	Yes, keep the tab on screen
Send a folder	Yes	Yes	Yes	Depends on the phone's file picker
Download single files	Yes	Yes	Yes	Yes
Save a whole folder with structure	Yes	ZIP or file by file	ZIP or file by file	ZIP or file by file
Chrome extension	Chrome and most Chromium browsers	—	—	—

Browsers change quickly; if something does not work, update the browser first.

Why must the sender stay online?

Because the files are on the sender's device, not on a server. 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. This is the price of not uploading and not storing your files. When you can't stay online, a cloud link is the right tool — see Why the sender must stay online.

What about long file names and paths?

Windows limits the length of a full file path. If a received file's path would be too long, StrongFolder shortens the name and adds a text file listing every renamed file, so nothing is lost silently.

Are there limits on what I may send?

Only send files you have the right to share. The Terms of Use apply to all transfers.

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Frequently asked questions

What is the maximum file size?

There is none set by StrongFolder. People send files from a few kilobytes to hundreds of gigabytes. The recipient needs enough free disk space.

Is there a limit on the number of files?

No limit is set by the service. Folders with many thousands of files work; very many tiny files transfer slower than one big file of the same total size.

How long does the link work?

The link works while the sender keeps sharing. When the sender clicks Stop Sharing or closes the tab, the files are no longer available.

Does it work on a phone?

Yes, in a mobile browser — but phones pause background tabs, so keep the StrongFolder tab on screen during the transfer. Saving whole folders with their structure needs a computer.

Can I resume an interrupted transfer?

If the connection drops, start the download again from the link while the sender is still sharing.

Does StrongFolder work behind a corporate firewall or VPN?

Usually yes. If a direct connection is blocked, the encrypted stream goes through a StrongFolder relay server. Some networks block WebRTC entirely; then try another network or ask the administrator.