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Very large files

Send a 40GB file for free, straight to the other device's disk.

Volo is built for very large files like 40GB, as long as the receiving browser can save straight to disk. The file travels directly between the two browsers, with no account and no copy uploaded or stored. This guide covers what that takes and what can get in the way.

Free · No sign-up · Files aren't uploaded or stored

How a 40GB file moves without filling memory

The sending browser never loads the whole file. It reads a 256KB slice, sends it over a WebRTC data channel, and reads the next. If the channel's send buffer backs up, the sender waits for it to drain before going on.

In desktop Chrome and Edge, the receiver uses the File System Access API. When you accept, the browser asks where to save, and each slice is written to that file as it arrives. If the disk falls more than about 8MB behind, the receiver asks the sender to pause until writing catches up, so memory use doesn't grow with the size of the file.

40GB is a design target, not a tested guarantee. Practical limits depend on the browser, the receiving device, free disk space, connection stability, and OS behavior.

See also:

What the sender and receiver need

  • Receiver: Chrome or Edge on a Windows, macOS or Linux computer. This is the setup where Volo saves straight to disk and sets no fixed size limit.
  • Sender: a modern WebRTC-capable browser on a phone or computer. Sending isn't capped at 1GB, because the file is read in slices rather than loaded whole.
  • Free space: more than the file's size on the drive you save to. A 40GB file needs over 40GB free there, plus headroom for anything else the computer is doing.
  • Time: both devices open, awake and online from the moment you accept until the last slice arrives.

Receiving on a phone, Safari or Firefox: the 1GB cap

Browsers without the File System Access API, including Safari on iPhone and Mac, Firefox, and most mobile browsers, have to hold an incoming file in memory until it's complete. Volo caps those receives at 1GB so a large file can't crash the tab.

For a bigger file, the Accept button on that device is disabled and the prompt suggests opening Volo in Chrome or Edge on a desktop instead. So for a 40GB file, the receiver has to be a desktop computer.

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What happens if a long transfer is interrupted

Volo can't resume. If either device sleeps, closes the tab or loses its connection, the other side notices within about 12 seconds and stops the transfer. The partly written file isn't completed, and you'd send it again from the start. Volo shows a warning when you pick a file over 2GB as a reminder of this.

  • Plug both devices into power and, if you can, turn off automatic sleep until the transfer finishes.
  • Keep the Volo tab open and visible on both. Volo asks the browser to keep the screen awake during a transfer where that's supported, but it can't stop the system suspending a tab in the background.
  • Put both devices on the same network if possible. A direct local route is the most reliable, and across networks there's no relay to fall back on if the path breaks.

Sending a 40GB file, step by step

  1. Open Volo on the receiving computer

    In desktop Chrome or Edge, open Volo and choose Create a room. The room shows a QR code, a room code and a Copy link button.

  2. Join from the device that has the file

    Scan the QR code, open the copied link, or type the room code into Join on the Volo home page. Both devices show that they're connected.

  3. Choose the file on the sender

    Drop the file onto the Files tab or click to browse. The receiver gets a prompt with the file's name and size; nothing is sent yet.

  4. Accept and choose a drive with enough space

    On the receiver, click Accept & Save…, pick a folder on a drive with more free space than the file needs, and confirm. Data starts flowing only now.

  5. Leave both devices alone until it reaches 100%

    Keep both tabs open and awake. When the progress bar completes, the file is closed and ready in the folder you chose.

Frequently asked questions

Can I send a 40GB file to an iPhone?

Not with Volo today. Browsers on iPhone receive into memory and are capped at 1GB, so the Accept button stays disabled for larger files. Send it to a desktop computer running Chrome or Edge instead.

Is 40GB the largest file Volo accepts?

No. 40GB describes the size of file Volo is designed for, not a cap and not a tested result. When the receiver saves to disk in desktop Chrome or Edge, Volo sets no fixed size limit; the practical ceiling comes from free disk space, browser and OS behavior, and how long the connection holds.

How long will a 40GB transfer take?

It depends on the connection between the two devices, so there's no single figure. A direct connection on the same local network is usually the quickest and most stable. The progress bar on both devices shows how far along it is.

Is the file compressed or changed on the way?

No. Volo sends the file's bytes as they are, in 256KB pieces, and the receiver writes them back out in the same order. There's no compression or re-encoding step.

Related guides

Start with the receiving computer

Open Volo in Chrome or Edge on the computer that will receive, create a room, and join it from the device with the file.