Fastest way to send large files: only send what they open
The fastest way to send a large file is to not send all of it. With KEIBIDROP the other person opens your file or folder in place, and only the parts they open cross the internet. If they need 2 GB out of a 50 GB folder, about 2 GB moves, and only those 2 GB land on their disk.
That saves hours of uploading and downloading, and the disk space of a full copy. It works with every app, because the shared folder looks like a normal folder, and in a browser tab a video plays the same way.
Most of a big file never needs to move
- A 50 GB project folder where they need three files.
- A two-hour video they want to watch for ten minutes.
- A 20 GB folder of logs where they search for one error.
- A game folder where they need the saves and leave the rest.
Each time, the usual route copies everything: upload it all, download it all, and keep a full copy on their disk.
The time and space you save
At 50 Mbps upload, full speed, before overhead:
| Job | Copy the whole thing | Open only what's needed |
|---|---|---|
| 2 GB of files from a 50 GB folder | 50 GB moves, about 2 hours 15 minutes, 50 GB on their disk | About 2 GB moves, about 5 minutes, about 2 GB on their disk |
| 10 minutes of a 4 GB, two-hour video | 4 GB moves, about 11 minutes before it plays | About 330 MB moves, and it starts right away |
Your disk keeps only what you opened
On-demand access means you view just what you want, and your disk keeps just that. A laptop with a 256 GB disk can browse a 2 TB folder on a NAS or on another computer, as long as what it opens fits. To keep a file for good, press Save.
We measured it on a normal home line
Two computers in one apartment in Bucharest, on a home line with 50 Mbps upload, connected through our relay. The shared folder had 2,683 files and 19.9 GB. Searching every log file in it and copying out the 382 MB that mattered moved 606 MB over the internet, 34 times less than the whole folder. The search across all the logs took 104 seconds. Recorded on 20 August 2026; the video is on the DFIR page.
Set it up once
- Connect the two computers in KEIBIDROP, with the steps on the how to use page.
- After the first connection the app asks if you want their files as a folder. Press the button. On a Mac it takes you to macFUSE, on Windows to WinFsp. Install it once and restart the computer once.
- Connect again. The screen says "Shared folder is live". Press Open Folder.
- Their files show up in a normal folder window. Open what you need, in any app.
No driver, or no install on their side? Press Invite link and they open single files in a browser tab: Play for videos and music, View for PDFs and photos.
Private the whole way
Everything is encrypted from one device to the other, and the encryption is quantum-safe: it's built to hold up even against future quantum computers. On a direct connection the file never touches our servers. When a firewall, a hotel Wi-Fi or a mobile network blocks a direct connection, our relay passes along encrypted pieces it can't read. Because only the opened parts move, nobody in the middle learns how big your folder is.
The computer that opens the folder needs a one-time driver: macFUSE on a Mac, WinFsp on Windows. The computer with the files has to stay on and connected.
When they do want the whole thing, Save copies it once, straight from your computer to theirs, with no upload step.
Teleport files: open them without downloading · Download KeibiDrop · KeibiDrop in your browser · Run it on a NAS · KeibiDrop for teams · Open one file from a 50 GB folder · Stream files without downloading them · Source code on GitHub