Practical guide
How to send large files without storing them in the cloud
A direct transfer avoids leaving a copy available for later download. With Senddfile, sender and receiver stay online together while the browser sends the file over WebRTC.
Start a transferWhen email and uploads are not the best fit
Email attachments usually have low size limits. Cloud services accept larger files, but first receive and store a copy. P2P transmission is useful when both people are available and prefer to send content directly without creating an account.
Send in four steps
- 1
Open Senddfile
Go to the transfer page in a modern browser.
- 2
Choose the file
Pick one file within the preventive limit of the receiving device.
- 3
Share the code
Send the short code to the recipient through a separate channel.
- 4
Keep both tabs open
Both devices need to stay online until the transfer finishes and the browser starts the download.
Direct transmission is not storage
Signaling helps the browsers find each other, but the file content is not written to Firestore or hosted by Senddfile. That is why there is no download link after the sender leaves.
Understand the P2P path and WebRTC's roleCheck the limit before you start
The receiving browser keeps the file in memory until it finishes. Senddfile applies preventive limits:
- 300 MiB in mobile browsers.
- 1 GiB in desktop browsers.
The limit does not measure free memory or guarantee success. A device with little available RAM can interrupt a smaller transfer.
What determines transfer speed
The rate mainly depends on the sender's upload, the receiver's download, network distance and quality, and device performance. P2P does not mean unlimited speed.
Common failures
- One device went offline or entered sleep mode.
- A tab closed or the browser released access to the selected file.
- A VPN, corporate network, or restrictive NAT blocked the direct connection; Senddfile does not offer a TURN relay yet.