Frequently asked questions
Answers about free large-file transfer, encryption, retention, and replacing PPAP.
Is it free?
Yes. Secufile is completely free with no sign-up. It is run by the Japanese non-profit PAPS (特定非営利活動法人ぱっぷす).
How large a file can I send?
Up to 10 GB and 100 files per transfer. Choosing a longer retention or more downloads lowers the limit a little.
Is it secure? Are files encrypted?
Files are encrypted with a password before they leave your device, so even the server operator cannot read them. The password is never stored, so no third party can recover a lost file.
How long are files kept?
You can set retention from 1 to 100 days. Files are deleted automatically when they expire or reach the download limit.
Can I use it instead of a password-protected ZIP (PPAP)?
Yes. It encrypts the file itself without making a ZIP, so it is a safer alternative to PPAP. Share the password through a different channel than the link.
Does it work on a phone?
Yes. Pick files or photos straight from your phone's browser and send them. There is no app to install.
Does the recipient need an account?
No. They just open the link and enter the password to download.
Can I delete a file I sent?
Yes. Create a management link when you send, and you alone can check download status and delete the share manually.
What is end-to-end encryption (E2EE)?
Files and filenames are encrypted and decrypted entirely in your browser, and neither the keys nor the password are sent to the server. No third party — including the operator — can decrypt the contents, in transit or while stored. Turn it on in the advanced settings when you need the highest confidentiality.
How does E2EE differ from the normal mode, and when should I use it?
The normal mode also encrypts with a password, so the server operator cannot read your files. E2EE goes further: the keys and password never reach the server, which suits confidential business documents or personal information where security comes first. Because encryption and decryption run in your browser it can be slower, and ZIP download and preview are disabled.
Can I have others send files to me? (a receive folder)
Yes. Create a request link under “Request files” and the other person can upload files to you without an account. Collect everything from your retrieve link — including a single ZIP download. Handy for gathering quotes or documents.
How is this different from other free file-transfer services?
Files are encrypted with a password before they leave your device, and you can optionally choose end-to-end encryption (E2EE). No sign-up and completely free; set the retention period and download limit, and files auto-delete when they expire. Pages that carry a password load no ads or analytics. It is run by the non-profit PAPS and never handles your data for profit.
Do I need to register or create an account?
No. Secufile is free and requires no sign-up. Both the sender and the recipient can use it without an account, and no email address is needed (you may optionally enter one only for receive-folder notifications).
What encryption does it use?
File bodies are encrypted with AES-256-GCM using a random per-file key, which is wrapped with a key derived from the share password via Argon2id. All traffic is encrypted with TLS (HTTPS). The password itself is never stored on the server, and file names are encrypted too.
Who can open files uploaded to a receive folder?
Only you. A receive folder uses public-key encryption: a key pair is generated in your browser when you create it. Only the public key is stored on the server, while the private key that opens the files stays in your browser. Submissions are sealed to your key, so neither the operator, nor the sender, nor other contributors can read them.
Can I send several files or folders at once?
Yes. You can select multiple files at once and drag-and-drop a whole folder. The recipient can download everything together (up to 100 files and 10 GB total per share).
Who runs it, and is it open source?
It is run by the non-profit 特定非営利活動法人ぱっぷす (PAPS) and is free to use. The source code is open on GitHub (MIT license).
If I forget the password, can the file be recovered?
No. The password is stored nowhere and cannot be recovered even by the operator — the flip side of “no one can read the files without the password.” We recommend using the auto-generated password.